Panama Canal: transit rules, tolls and NeoPanamax limits

The Panama Canal is an 80 km lock canal across the Isthmus of Panama, connecting the Caribbean Sea at Colon with the Gulf of Panama at Balboa, operated by the Panama Canal Authority (Autoridad del Canal de Panama, ACP) since 31 December 1999. It is not a sea-level cut. Ships are lifted through locks 26 m into Gatun Lake, carried across the isthmus on fresh water, and lowered back to the sea at the far end, which makes the canal’s capacity a water budget as much as a channel. That single fact separates it from the Suez Canal and explains almost everything a practitioner needs to know about it: why the ship-size limits are fixed boxes, why the maximum draft moves with rainfall, and why a dry year forces the Authority to ration transits.

Two chamber geometries define the traffic. The original 1914 locks fixed the Panamax envelope at 294.13 m length overall, 32.31 m beam and 12.04 m tropical fresh water draft. The NeoPanamax locks, opened on 26 June 2016 and enlarged twice since, take vessels to 370.33 m, 51.25 m and 15.24 m TFW. The ACP carried 13,404 transits and 489.2 million PC/UMS tons in the fiscal year to 30 September 2025, which its Annual Report 2025 describes as nearly 3 percent of global maritime trade.

Route, lock geometry and how a lock canal works

The canal crosses the isthmus in three steps up and three steps down, with a freshwater lake as the summit reach, and every one of its commercial constraints follows from that arrangement. A ship entering from the Atlantic is raised 26 m in the Gatun or Agua Clara flight, crosses Gatun Lake , passes through the Culebra Cut , and descends through Pedro Miguel and Miraflores, or through Cocoli, to the Pacific. The lift is what makes the canal possible across the Continental Divide, and it is also what caps the fleet: a lock chamber is a fixed box, and the box decides the ship.

Alignment, the Culebra Cut and the summit reach

The canal runs northwest to southeast, so the Pacific entrance at Balboa lies further east than the Atlantic entrance at Colon. That is a consequence of the S-shape of the isthmus and it surprises most people who have not looked at the chart. Total length is about 80 km deep water to deep water, of which the navigable channel through Gatun Lake accounts for the largest single stretch.

The Culebra Cut, officially renamed Gaillard Cut on 27 April 1915 for David du Bose Gaillard, who headed the Central Division and died in December 1913, runs about 13.7 km through the rock and limestone of the Cordillera Central. It is the section that defeated the French, and its slopes have needed management ever since. The canal has operated around the clock since 12 May 1963, when fluorescent lighting at the locks and through the Cut made night transits routine.

The original locks and the Panamax envelope

The Panamax class is an artifact of chambers built before the First World War. The ACP gives the original chambers as 33.53 m wide and 304.8 m long, paired in two lanes at each of the three stations so that upbound and downbound traffic can move at once. The widely repeated figure of 320 m is the overall structural length rather than the usable chamber, and the ACP does not publish it.

The vessel limits that follow are tighter than the chamber. N-1-2026 defines a Panamax vessel as one of 30.48 m beam or more complying with 294.13 m (965 ft) LOA, 32.31 m (106 ft) beam and 12.04 m (39 ft 6 in) TFW draft, and then sets a lower operational maximum length of 289.6 m (950 ft), except for passenger and container ships at 294.43 m (966 ft). A beam of 32.4 m to 32.9 m may be permitted case by case with prior approval where the deepest immersion does not exceed 11.3 m TFW. A first transit by any vessel over 274.32 m LOA requires plan approval in advance.

The 32.31 m beam is the number that shaped a generation of ships. It leaves room for 13 container rows on deck, and the 13-wide deck was the visual signature of the Panamax container ship for three decades. The same limit fixed the dimensions of the Panamax bulk carrier , which remains a working class on coal and grain routes that have nothing to do with the canal.

The NeoPanamax locks and the current envelope

The expanded locks are far larger than the ships they take, because the chamber has to hold the ship plus the water around it. The ACP gives the Agua Clara and Cocoli chambers as 427 m (1,400 ft) long, 55 m (180 ft) wide and 18.3 m (60 ft) deep. Those are chamber dimensions, not vessel limits, and confusing the two is the most common error in secondary coverage of the expansion.

The vessel limits under N-1-2026 are 370.33 m (1,215 ft) LOA, 51.25 m (168.14 ft) beam and 15.24 m (50.00 ft) TFW draft. They were not set in 2016 and have moved twice. The locks opened on 26 June 2016 with a 49.00 m beam limit and a 367.28 m length limit. The ACP raised the beam to 51.25 m effective 1 June 2018, which admitted the Q-Flex LNG carrier class and lifted LNG transits from 181 in 2017 to 340 in 2018. It raised length overall to 370.33 m in May 2021, stating that 96.8 percent of the world container ship fleet could then transit.

The 49.00 m and 366 m figures still circulate because both survive in the notice for different purposes. An integrated tug and barge combination is limited to 366.0 m including the tug, and a dead tow to 49.00 m beam and 400.0 m aggregate length including the accompanying tugs. A source quoting 49 m as the NeoPanamax beam limit is quoting the dead-tow rule or a 2016 figure.

Figures from OP Notice to Shipping N-1-2026, effective 1 January 2026. Chamber dimensions from the ACP’s published description of the original and expanded locks.

Air draft and the Bridge of the Americas

Air draft is a hard limit at Panama and it is set by the Authority rather than by a published bridge clearance. N-1-2026 allows 57.91 m (190 ft) from the waterline to the highest point, at any state of the tide, for any vessel transiting the canal or entering the Port of Balboa. With prior permission of the Transit Operations Division Executive Manager a height to 62.5 m (205 ft) may be permitted case by case, with passage at mean low water springs at Balboa.

The ACP states the reasons: tide, the unpredictable upward movement of water from swells and surges, and maintenance equipment suspended beneath the bridge at Balboa. That last reason is why the figure is an operational limit and not a fixed structural clearance, and why an operator planning an air-draft-critical transit asks the Authority rather than reading a chart. A separate rule requires a minimum clearance of 1,000 mm from all equipment above the lock walls.

Speed, trim and under-keel margin

The canal requires a ship to be able to move. N-1-2026 defines minimum full ahead speed as 8 knots, the speed the Authority has determined is needed to complete a transit in standard times, and a vessel unable to develop and maintain it is assessed additional pilots. Drag beyond 1.83 m (6 ft) or 1 percent of LOA, whichever is greater, counts as adverse trim.

The draft limits themselves are built on a stated margin. The Authority sets them to provide a safe navigational margin of at least 1.52 m (5 ft) over critical elevations, with a clearance over the south sill of Pedro Miguel Locks of 0.50 m (1 ft 8 in) at a Miraflores Lake level of 16.61 m (54 ft 6 in). Those are the numbers the under-keel clearance calculation for a canal transit actually rests on, and they are why the draft moves when the lake does. Vessels above 37.1 m beam in the NeoPanamax locks must tie up.

Maximum vessel dimensions and the size classes the canal created

Panamax and NeoPanamax are canal categories, not class-society or IMO categories, and the ACP uses two different definitions of NeoPanamax for two different purposes. That distinction costs money and it is not widely understood. The transit-limit definition in N-1-2026 governs whether a ship physically fits. A separate toll-assessment definition governs what it pays.

For transit, a NeoPanamax vessel is one using the new locks within the 370.33 m, 51.25 m and 15.24 m envelope. For tolls, the February 2026 tariff defines a NeoPanamax vessel as one with beam over 32.61 m (107 ft) or LOA over 294.44 m (966 ft), plus any vessel transiting at 12.12 m (39 ft 9 in) TFW or greater, plus any vessel that a condition or deficiency forces through the NeoPanamax locks. A Panamax Plus vessel is a Panamax-dimension ship authorized above 12.12 m TFW, which pushes it through the new locks and charges it as NeoPanamax.

Which classes are excluded, and where they go

Beam excludes more ships than draft or length. The largest container ships in service exceed 61 m in beam, well past the 51.25 m limit, so the Asia to Europe ULCV fleet has no canal option and never has. Those ships run through Suez or around the Cape of Good Hope . Q-Max LNG carriers are excluded on beam for the same reason, while Q-Flex was admitted by the 2018 increase.

A laden Capesize bulk carrier can physically use the new locks, but most iron ore voyages still route around the capes because the toll does not repay the distance saved. The point generalizes: the canal competes on time, and a ship whose cargo is not time-sensitive often declines the trade. Ships too large for the locks on an Asia to United States East Coast rotation route via Suez or the Cape of Good Hope, or transship. Cape Horn is effectively absent from scheduled liner service.

Why the draft figure changes

The published maximum draft is a conditional statement, and reading it as a fixed number is the single most expensive mistake a charterer can make at Panama. The 12.04 m Panamax maximum applies at a Gatun Lake level of 24.01 m (78.8 ft) or higher. The 15.24 m NeoPanamax maximum applies at 25.91 m (85.0 ft) or higher. Below those levels the Authority reduces the allowable draft to preserve the navigational margin.

The reduction triggers are separate from the qualifying levels and are also separate from each other. N-1-2026 states that as the lake falls below 25.91 m it becomes necessary to reduce the NeoPanamax draft, and below 24.09 m (79 ft) to reduce the Panamax draft. Reductions are made in 15.24 cm (6 in) decrements with three weeks’ advance notice where possible, based on lake level and precipitation forecasts by the Authority’s hydrologists and meteorologists.

The mechanics protect a ship already committed. Ships loaded to a prevailing draft limitation when a new restriction is promulgated are waived for transit, subject to overriding safety considerations. Ships loading after promulgation are held to a tolerance of not more than 15.24 cm and may be required to trim or off-load. A vessel intending an initial transit above 10.82 m (35 ft 6 in) must submit the information required by Article 52 of the ACP Navigation Regulations and request its maximum authorized draft not later than two weeks before loading.

Tolls: PC/UMS, the two-component tariff and what a transit costs

A Panama Canal toll is a fixed component plus a capacity component plus surcharges, and it has been built that way since 1 January 2023. Before that restructure the toll was essentially a rate applied to a measured quantity, which is how most secondary sources still describe it. The change matters commercially because the fixed component is large, it does not scale with the cargo, and it falls hardest on a partly loaded large ship.

PC/UMS net tonnage, and why it is not gross tonnage

PC/UMS is a canal-specific tonnage that shares one variable with the international system and nothing else. Article 10 of the ACP Regulations for the Admeasurement of Vessels, approved by ACP Agreement No. 358 of 12 December 2019, defines PC/UMS Net Tonnage as K4(V) plus K5(V), where V is the total volume of all enclosed spaces in cubic metres. That V is identical to the V of the International Convention on Tonnage Measurement of Ships, 1969 , and the length term uses the ITC-69 definition. The coefficients are where the two part company. ITC-69 gross tonnage is K1 times V with K1 equal to 0.2 plus 0.02 log10(V); the ACP’s K4 is {0.25 plus [0.01 log10(V)]} times 0.830, and K5 falls to zero for essentially every cargo ship, since it vanishes where the depth-derived term DA is 20.0 m or less.

Working the two published formulae against each other gives PC/UMS at roughly 82 to 84 percent of ITC-69 gross tonnage for a conventional cargo ship. That is arithmetic from the two instruments rather than a figure the ACP publishes, and it is offered here as an order-of-magnitude check rather than a substitute for admeasurement. Passenger ships behave differently: the ACP disapplies the ITC-69 Regulation 2 treatment of excluded spaces and counts balconies, pools and corridors in V, so a cruise ship’s PC/UMS sits materially above what the ITC-69 approach would give.

Tolls have been assessed on PC/UMS since 1 October 1994. A net Panama Canal ton is equivalent to 100 cubic feet of volumetric capacity. The system is separate again from Suez Canal Net Tonnage , so one hull carries three different tonnage figures depending on which authority is asking, and the fuller treatment of the ACP formula is in the Panama Canal Universal Measurement System article.

Admeasurement is the Authority’s own function. Article 19 provides that it is carried out by the Authority’s specialized personnel or by agents it authorizes, and Article 20 requires the Authority to deliver the ACP Toll Basis Certificate, kept aboard as proof the vessel has been inspected and measured. Article 21 reserves the right to correct it. A classification society does not issue this certificate, whatever it may issue for tonnage measurement under ITC-69.

The billing unit is not the same for every ship

Article 10 sets a different charging parameter for each segment, so the question “what is the rate per ton” has no single answer. Full container vessels are charged per TEU on Total TEU Allowance, the sum of the above-deck and below-deck allowances, using a published conversion table in which a 20 ft by 8 ft by 8.5 ft unit is 1.00 TEU, a 40 ft high-cube is 2.24, and a 45 ft unit is 2.51. Dry bulk is charged on deadweight, or on timber deadweight where the vessel holds a valid timber summer draft and carries timber on deck, whichever is greater. Gas carriers are charged per cubic metre of capacity. Warships, dredges, floating drydocks and other floating equipment are charged on maximum fully loaded displacement in metric tons.

Passenger vessels split on a ratio test. A passenger ship over 30,000 GT under ITC-69 whose PC/UMS-to-passenger ratio is 33 or less is charged per berth; every other passenger vessel is charged on PC/UMS. PC/UMS is the capacity unit only for tankers, chemical carriers, vehicle carriers and RoRo, general cargo, reefers, other vessels, and those passenger ships that fail the ratio test.

The fixed component

The fixed charge is levied per transit on the toll-assessment size category and the locks used, and it is the part of the 2022 restructure that changed voyage economics most.

A Regular vessel has a beam under 27.74 m (91 ft) and a Super vessel a beam of 27.74 m or more. Rates from the ACP consolidated tariff, February 2026 revision.

The capacity component

The capacity rates in force through 2026 took effect on 1 January 2025. Tankers pay USD 6.00 per PC/UMS ton as a Regular vessel, USD 5.25 as a Super and USD 3.25 as a NeoPanamax; chemical carriers USD 5.50, 5.25 and 3.25. LPG carriers pay USD 3.50, 3.85 and 2.75 per cubic metre, and LNG carriers USD 3.50, 3.85 and 2.05. Dry bulk pays USD 1.65, 1.50 and 0.80 per deadweight ton. Vehicle carriers and RoRo pay USD 6.00, 4.75 and 2.75 per PC/UMS ton. General cargo and reefer vessels pay USD 3.50 below PC/UMS 10,000 and 3.25 at or above, then 3.00 as a Super and 1.50 as a NeoPanamax.

Container ships pay on three separate TEU counts. Total TEU Allowance is charged at USD 40.00 for Regular and Super vessels and USD 30.00 for NeoPanamax in both bands. Loaded TEU is charged at USD 35.00 across Regular, Super and NeoPanamax under 10,000 TTA, rising to USD 45.00 for a NeoPanamax with TTA of 10,000 or more. Empty TEU is charged at USD 6.00 throughout. On-deck containers carried on a non-container vessel are charged separately at USD 120.00 reefer, USD 110.00 dry and USD 70.00 empty.

Ballast tolls run at 85 percent of laden tolls on the fixed and capacity components under item 1010.BA01, and the concession does not apply to full container vessels at all. An LPG carrier qualifies while carrying up to 2 percent of certified cargo capacity and an LNG carrier up to 10 percent as heel. Displacement-charged vessels pay USD 5.50 per ton. A small vessel pays a flat rate by length, from USD 2,130 under 19.812 m (65 ft) to USD 6,000 above 30.480 m, up to 125 ft LOA.

The Fresh Water Charge

The Fresh Water Charge is a water scarcity charge on every vessel over 38.1 m LOA using either lock system, and it was introduced on 15 February 2020, not in 2023. It has a fixed and a variable part. The fixed portion is USD 4,000 for vessels from 38.1 m to 91.44 m (300 ft) LOA and USD 10,000 above 91.44 m, both effective 1 January 2024. The variable portion is a sigmoidal function of the official Gatun Lake level in feet, rounded to one decimal, as registered at 1200 hours the day before transit, and it yields 0 to 10 percent of the vessel’s total tolls including both the fixed and capacity components.

The design is deliberate: the charge rises as the lake falls, so the price signal tracks scarcity rather than cost. The variable component was modified with effect from 1 October 2023, roughly halving it, and the two-band fixed portion dates from 1 January 2024.

The 2022 restructure and what it changed

The current tariff is the settled state of one restructure, not a series of ad hoc increases. The ACP issued its proposal on 1 April 2022, received written comments from 17 interested parties and held a public hearing in Panama on 20 May 2022. The Cabinet Council approved the result on 13 July 2022, and it was implemented in three programmed steps on 1 January 2023, 1 January 2024 and 1 January 2025.

The restructure introduced the fixed tariff per transit for the first time, replaced container pricing bands with a capacity tariff on Total TEU Allowance, kept the loaded-TEU tariff while adding an empty-TEU tariff and abolishing the return-voyage loaded tariff, and collapsed six loyalty categories into one. The customer loyalty programme paid 95 percent of regular tolls from 1 January 2023 for customers deploying more than 1.5 million TEU of allowance per year, 97.5 percent from 1 January 2024, and was eliminated entirely from 1 January 2025. There was no toll increase on 1 January 2026: every item 1010 row in the February 2026 consolidated tariff still carries a 2023, 2024 or 2025 effective date.

Booking a transit: the reservation system, LoTSA and the auction

A ship gets through the Panama Canal either on a booked slot or in the queue, and the difference between the two is now measured in days and, at auction, in millions of dollars. The transit reservation system in OP Notice to Shipping N-7-2026 sets out the periods, the allocation rules and the fee ladder. The Authority reissued that notice on 1 July 2026 and stated that it will henceforth be revised in January and July of each year rather than annually.

Booking periods and how slots are allocated

Slots open in defined windows ahead of the transit date. Period 1 runs 90 to 15 days ahead for the Panamax locks and 90 to 31 days for the NeoPanamax locks. Period 1.a is NeoPanamax only, 30 to 15 days. Period 2 runs 14 to 8 days and Period 3 runs 7 to 2 days, opening at 0700 and closing at 1500. Commercial passenger vessels have a Special Period running 730 to 366 days ahead, allocated 1 NeoPanamax, 3 Super and 2 Regular slots, with NeoPanamax passenger turn-around transits limited to one per day. Unused slots carry forward.

Allocation in Periods 1, 1.a and 2 is by competition ranked on the ACP Customer Ranking, with first come, first served applying only after that competition closes. Date changes, substitutions and swaps are permitted 365 to 91 days out even where no booking period is open. A Panamax Plus vessel, authorized above 12.04 m TFW, is excluded from the ordinary booking process and may be admitted to auction for a NeoPanamax slot when the Authority determines, limited to one vessel per transit date.

The reservation fee itself is tiered: USD 12,000 Regular, USD 50,000 Super and USD 100,000 NeoPanamax, all effective 1 January 2025. A last-minute reservation costs USD 25,000, USD 100,000 and USD 200,000 respectively. Just-in-time service is USD 4,000 through the Panamax locks and USD 10,000 through the NeoPanamax locks, and a guaranteed daylight transit for an unrestricted Regular vessel is USD 30,000.

Cancellation, date change and late arrival

The fee ladder is steep and it is where an operator loses money on a slot it cannot use. Cancellation costs 50 percent of the reservation more than 90 days out, rising through 60, 70 and 80 percent to 100 percent within 4 days, with an additional surcharge of 250 percent for a cancellation under 2 days. Date changes run 60 to 100 percent on the same shape of ladder. A late arrival costs 25 percent of the reservation within an hour, 50 percent between one and two hours and 100 percent beyond two hours, with a 50 percent charge for just-in-time non-compliance. Swaps are included beyond 14 days and cost 1 percent inside it; substitutions run from USD 500 beyond 30 days to 80 percent within 4 days.

LoTSA slots carry their own penalties: 80 percent of the awarded bid for a cancellation 15 days or more ahead, effective 1 November 2025, and 100 percent inside 15 days of the required arrival time, effective 6 January 2026.

LoTSA and the NetZero Slot

LoTSA, the Long Term Slot Allocation, awards packages of weekly or monthly NeoPanamax slots to the highest bidders in a sealed-bid auction, ties broken by order of receipt. It is now the principal long-horizon mechanism and it is expensive: the ACP Annual Report 2025 records 900 LoTSA slots billed between 5 January and 30 September 2025 for B/.251 million, an average of about B/.278,000 per slot. The first LoTSA 2.0 sealed-bid round ran on 28 October 2025, moving the programme to two six-month cycles instead of a twelve-month horizon and cutting the average daily allocation from four slots to three. LoTSA 2.5 followed on 16 May 2026, covering transit dates from 5 July 2026 to 2 January 2027.

The NetZero Slot is newer and narrower. One weekly NeoPanamax slot is drawn from Booking Period 1.a and allocated by a competition held between 0800 and 0830 on the day that period opens. A vessel qualifies only if it is registered as dual fuel and capable of operating on at least one fuel with an approximate well-to-wake carbon intensity of 75 gCO2e/MJ or lower, which covers dual-fuel LNG, LPG, methanol and ammonia . A first-time transit is ineligible until the Admeasurement Unit has inspected the vessel. Allocation runs laden before ballast, then higher PC/UMS, then highest combined tolls and marine services. The winner pays the standard NeoPanamax reservation fee and receives a choice of date within the offered week, a guaranteed 24 hours in-transit time, and just-in-time service included.

That is a canal authority pricing a fuel choice into waterway access, which is unusual and worth noting for what it signals about how scarce capacity gets rationed.

The auction

Auctioned slots are offered only during Booking Period 3, save that the NeoPanamax conditioned slot may be auctioned the day after the Period 2 tiebreaker. There is no ceiling but there is a floor: a base amount per category set in the Official Maritime Tariff, and a minimum bid of USD 100,000 for the special NeoPanamax conditioned-slot auction. Daily auctions normally open no earlier than 1400, and the closing time extends automatically by two minutes if a bid arrives in the final window. The highest bid wins and ties go to the earliest. A vessel awarded an auctioned slot may not bid in subsequent auctions for the same date, and an unawarded auction between seven and four days out may be re-offered at four days.

The ACP does not publish individual auction results. Every reported clearing price comes from the buyer, a broker or the trade press, and should be read on that basis. The Authority has said at an aggregate level that average auction prices rose from about USD 135,000 to USD 140,000 in March 2026 to about USD 385,000 in April 2026. The most widely reported individual figure remains the USD 3.98 million paid on 8 November 2023 by Japan’s Eneos Group for a slot for the 50,000 dwt LPG carrier Sunny Bright, against earlier reported records of USD 2.85 million in October 2023 and USD 2.6 million in November 2022, the last of which predates the drought entirely.

Gatun Lake, the water balance and the drought constraint

Gatun Lake is the canal’s operating reservoir, its drinking-water source and its binding constraint, and rainfall in the Chagres watershed sets the daily transit ceiling. Every lockage spends fresh water that flows by gravity from the lake to the sea and is not recovered. That is the structural difference from a sea-level canal: weather cannot close Suez, and it has twice forced Panama to ration.

The lake operates between a maximum of 26.7 m (87.5 ft) and a minimum operating level of 24.8 m (81.5 ft). Its surface covers about 422 km2. Deepening work raised active storage from 770 million m3 to 1,420 million m3, close to 45 percent. The watershed itself covers 3,338 km2, with a median annual rainfall of 2,630 mm across 20 representative gauges over 1950 to 2021 and a wettest sub-basin averaging 4,852 mm. The same watershed supplies about 95 percent of the drinking water for Colon, Panama City and San Miguelito, serving roughly 2.5 million people, which is why navigation is not the only claim on it.

What a transit actually costs in water

The ACP measures water use per transit and publishes it. In FY2025 the average was 0.194 hm3 (194,000 m3) per Panamax vessel transit, representing 88 percent of an equivalent lockage, and 0.4368 hm3 (436,800 m3) per NeoPanamax vessel transit, of which 0.2432 hm3, or 56 percent, was consumed for Gatun reservoir water quality conservation rather than for moving the ship. The frequently quoted figure of 52 million US gallons per transit is the same Panamax quantity in different units: it converts to 196,841 m3.

Subtracting the water-quality component from the NeoPanamax figure leaves about 0.194 hm3 for the lockage itself, which is close to the Panamax figure despite a chamber more than three times the volume. That subtraction is arithmetic from the ACP’s own published numbers rather than a claim the Authority makes, and it is the honest way to read the water-saving basins: they hold the lockage cost of a much larger ship roughly level, and they do not reduce total consumption, because the water-quality obligation was added on top.

Total lock water use in FY2025 was 3,179 hm3, split 53 percent at the Panamax locks and 47 percent at the NeoPanamax locks, averaging 8.68 hm3 per day. Watershed inflows ran 6,348 hm3, about 11 percent above the historical average, and the average lake level of 26.53 m sustained the full 50 ft and 39.5 ft drafts through the dry season. Salinity in the Gatun navigation channel averaged 0.2403 psu, 18.4 percent below the FY2020 maximum.

The water-saving basins

Each NeoPanamax chamber has three lateral water-saving basins , nine per lock complex and 18 across Agua Clara and Cocoli, and they reuse up to 60 percent of the water in each lockage. The 60 percent is measured against what the same large chamber would consume without basins, not against the smaller Panamax chambers, and reading it as a saving against the old locks overstates it. The Panamax locks have no basins and instead use cross-filling between the paired lanes as a conservation measure, which saved 109 hm3 in FY2025, all of it at Pedro Miguel and none at Gatun, equal to a layer of 0.25 m across the lake.

The 2023 restriction, and what actually happened

The 2023 and 2024 drought was the first time in the canal’s history that transits had to be restricted. Capacity fell to approximately 32 vessels per day from 30 July 2023. October 2023 precipitation was the lowest on record since 1950, at 41 percent below normal, and 2023 ranked as the second driest year for the period.

Advisory to Shipping A-48-2023 of 30 October 2023 then published a descending schedule: 25 slots from 3 to 6 November 2023, 24 from 7 to 30 November, 22 through December, 20 through January 2024 and 18 per day from 1 February 2024 until further notice. The Advisory stated its purpose plainly, which is the part usually lost in summary: the reductions were intended to postpone the need for further draft reductions below the then-current 13.41 m (44 ft) TFW NeoPanamax limit. The slot cut was the instrument chosen to protect the draft.

The 18-per-day floor was never reached. Better than expected November and December rainfall, together with the measures already in force, allowed the ACP to announce on 15 December 2023 that capacity would instead rise to 24 daily transits from 16 January 2024. Recovery ran through 2024: the NeoPanamax draft returned to 13.71 m (45 ft) from 15 June 2024 and to 14.94 m (49.0 ft) by August 2024, and daily transits reached 33 from 11 July 2024 and 34 from 22 July 2024. The ACP recorded no draft restrictions at all in FY2025.

The 2026 restriction

Restrictions returned in 2026 and were live as this article was last revised on 2 September 2026, so every figure in this section is dated and must be checked against the current advisory before a fixture. Advisory A-22-2026 of 1 July 2026 set the NeoPanamax maximum authorized draft at 14.94 m (49.0 ft) TFW from 24 July 2026 and 14.78 m (48.5 ft) from 15 August 2026. The Authority announced two further steps on 5 August 2026, to 14.63 m (48.0 ft) and 14.48 m (47.5 ft), following conservation measures in place since December 2025.

Advisory A-29-2026 of 20 August 2026 then postponed both remaining draft steps, to 2 September and 1 October 2026 respectively, and cut slots instead: NeoPanamax to 9 and Panamax to 25 daily from 3 September 2026, with Panamax falling to 23 from 15 September. NeoPanamax allocation was set to prioritize full container vessels of the highest TEU capacity, with Customer Ranking as the tiebreaker, and auction slots were divided into four vessel groups covering gas carriers, dry bulk and general cargo, container and vehicle carriers, and tankers. In-transit time was set at 48 hours for all booked vessels from 4 September 2026. The Authority had reported in July 2026 that the probability of a severe El Nino over the watershed had risen from 25 percent in April to 81 percent.

The Rio Indio reservoir

The ACP’s answer to structural water scarcity is a new reservoir, and it is approved rather than built. Board Resolution ACP-JD-RM 25-1542 of 21 February 2025 approved the resources for a new lake, the Rio Indio reservoir , in the middle course of the Indio River watershed, at a budget of about B/.1.6 billion and a build time of about six years, with the tender now planned for 2027. The Cabinet Council declared it a project of public interest, so land sales, new construction, loans, land-use changes and economic activity in the area of influence require ACP prior approval.

The project requires flooding inhabited land. Published figures put the affected area at about 4,600 hectares and the affected population at roughly 38 farming communities, with resettlement estimates around 2,000 to 2,300 people and a comparable number partially affected. A resettlement census began in August 2024. Local opposition has been sustained, and an alternative expansion of the Bayano reservoir requiring no relocation has been proposed. No funded and committed completion date exists, so the reservoir does not bear on transit planning for the next several years.

Governance: the ACP, the treaty basis and the neutrality regime

The Panama Canal Authority is an autonomous Panamanian constitutional entity, not a company and not an arm of the shipping industry, and its powers come from Title XIV of the Political Constitution and Law 19 of 11 June 1997. The United States handed over operation at noon on 31 December 1999, when the Panama Canal Treaty of 1977 terminated by its own terms under Article II(2). Panama was the territorial sovereign throughout the American period; what ended was a grant of operating rights.

Board, administrator and the limits on both

Article 13 of Law 19 composes the Board of 11 directors: one designated by the President of the Republic, who chairs the Board and holds the rank of Minister of State for Canal Affairs; one designated by the Legislative Branch and freely appointed and removed by it; and nine appointed by the President with the consent of the Cabinet Council and ratified by an absolute majority of the Legislative Assembly. Terms run nine years, staggered on the first board at three, six and nine.

The Administrator is not a director. Article 18(1) gives the Board the power to appoint and remove the Administrator, Deputy Administrator and Inspector General, and bars it from designating a sitting director to any of those posts. Directors are unpaid beyond a per diem, may not contract with the Authority during their term or for two years afterward, and must resign six months before an election to stand for office.

How tolls are actually set

Article 9 gives the Authority the power to set tolls, fees, rates and the admeasurement rules, and Article 18(2) gives the Board the admeasurement system on prior consultation with the Administrator. But Article 18(3) makes the tolls subject to final approval of the Cabinet Council, and Article 79 requires a written-comment process and a public hearing held at least 30 days after the notice calling it is published. Describing canal tolls as set unilaterally by the ACP is wrong in Panamanian law. It is accurate only in the sense that no international body has any role: the IMO does not set canal tolls and Panama the state, not the Authority, is the IMO member.

Article 75 tells the Board what the tolls have to cover: operating costs including depreciation, support for water resources protection, working capital and reserves, payments to the National Treasury, capital for plant replacement and modernization, interest on the assessed value of the canal, and losses carried over, taking into consideration safe, uninterrupted, efficient, competitive and profitable service. Article 76 forbids the Government and the Authority from granting any exemption from tolls save for vessels exempted by treaties in force ratified by Panama. Article 10 exempts transiting vessels, cargo, passengers, owners and operators from every other national or municipal tax, fee, charge or levy, which is why the toll is the whole of the fiscal burden of a transit.

The neutrality regime and what it obliges

The Treaty Concerning the Permanent Neutrality and Operation of the Panama Canal, signed on 7 September 1977 and in force from 1 October 1979, has no termination date and remains the governing international instrument. Article II keeps the canal secure and open to peaceful transit by the vessels of all nations on terms of entire equality, with no discrimination against any nation concerning the conditions or charges of transit. Article III(1)(c) requires that tolls and other charges be:

just, reasonable, equitable and consistent with the principles of international law.

The final limb is routinely dropped in summary and it is the one that carries legal weight. Article III(1)(a) confines the conditions of transit and the rules to those necessary for safe navigation and efficient, sanitary operation. Article III(1)(e) allows warships and auxiliaries of all nations to transit irrespective of internal operation, propulsion, origin, destination or armament, without inspection, search or surveillance as a condition of transit, subject to health and quarantine certification. Annex A then defines inspection so as to exclude the measures strictly necessary for admeasurement, and defines internal operation so as to exclude the measures necessary to transit vessels under the control of pilots, which is the treaty basis for both ACP admeasurement of warships and compulsory pilotage.

What the toll clause does not do is give a customer a forum. It states a substantive standard with no dispute-resolution mechanism inside the treaty, and it constrains discrimination between nations rather than differentiation between ship types. A USD 300,000 fixed fee on a NeoPanamax box ship against USD 15,000 on a small general cargo vessel is differentiation by size and locks used, and it does not engage the clause. The route for a customer with a tariff objection is the Article 79 hearing and, ultimately, the Cabinet Council.

Article VI says nothing about toll-free passage for the United States, a point on which secondary coverage is persistently wrong. Article VI(1) entitles warships and auxiliaries of the United States and Panama to transit expeditiously and irrespective of internal operation, propulsion, origin, destination, armament or cargo. The only toll-free entitlement in the instrument is Article VI(2), which concerns Colombia’s toll-free transit while the United States had operating responsibility and thereafter permits Panama to provide toll-free transit to Colombia and Costa Rica. At tariff level, the February 2026 notes exempt United States and Panamanian warships and auxiliaries from the vessel scheduling fee and the last-minute reservation charge by reference to the Neutrality Treaty, which is a fee waiver and not a toll waiver; warship tolls remain assessable at USD 5.50 per displacement ton. The treaty sequence and the sovereignty analysis are treated at length in the Panama Canal Treaties of 1977 article.

Port concessions are not canal operation

The container terminals at Balboa and Cristobal sit next to the canal’s Pacific and Atlantic entrances and are licensed by the Autoridad Maritima de Panama under a port concession . They are not part of the canal, they are not operated by the ACP, they handle no transits, and their operator has never had any role in transit scheduling, tolls, pilotage or admeasurement. When the Panama Supreme Court ruled the Panama Ports Company concession unconstitutional on 29 January 2026, and the ruling became final on publication in the Gaceta Oficial on 23 February 2026, what was struck down was a port concession. No canal function changed and no ACP instrument was affected. The conflation of the two is the most common error in coverage of the dispute.

Transit operations, special cargoes and discharge rules

A Panama Canal transit is conducted under the control of an ACP pilot, with tugs and, in the original locks, electric locomotives, and the Authority’s own rules on cargo and discharges are stricter than the international baseline in several places. That last point matters most: an operator who assumes the IMO regime applies inside canal waters will get it wrong on ballast water, on sewage and on single-hull tankers.

Pilotage, tugs and locomotives

Pilotage is compulsory and the ACP pilot has control of the navigation of the vessel, which is not the usual arrangement. In most compulsory pilotage regimes the master retains command and the pilot advises. Regular transit pilotage carries no separate charge because it is bundled into the toll. A narrow exemption exists for non-commercial Panamanian-registered vessels under 65 ft with 6 ft draft or less operating locally between the canal entrances and Balboa or Cristobal, operated by personnel licensed for canal waters.

Additional pilots are assessed for named deficiencies: restricted visibility, inadequate sanitary facilities, inability to relay, vessel configuration, and inability to develop and maintain the minimum full ahead speed of 8 knots. As at April 2026 the Authority reported a transit pilot force of 295 with 10 pilots in training, 48 tugs and 100 locomotives. The locomotives, or mules, work the original lock chambers; the NeoPanamax locks are worked by tugs rather than locomotives.

If a transit is aborted through no fault of the ACP before the vessel completes lockage through the first set of locks, it pays port pilotage and the channel fee. Once it has completed that first lockage it pays the full prescribed tolls and all other charges. Delay charges apply after a grace period of four hours before the scheduled lockage, or 30 minutes once the pilot is aboard.

Transit time, in two measures

The ACP publishes two figures monthly and they answer different questions. In-Transit Time averaged 11.84 hours in April 2026, with a high of 14.22 and a low of 9.77, and 10.2 hours in February 2026. Canal Waters Time, which includes waiting, averaged 32.33 hours in April 2026 against 19.1 hours in February 2026, with an April high of 56.72 hours. The gap between the two is the queue and it is the number that moves a voyage estimate. Daily arrivals averaged 40.5 against 38.70 oceangoing transits in April 2026, and NeoPanamax vessels of 107 ft beam and over made up 308 of 1,161 transits, or 26.53 percent. The ACP does not publish a transit time split by lock type, so any figure claiming one is not from the Authority.

Dangerous cargo and the Precaution Designator

Dangerous cargo requires advance notice of intent under Article 41 of the ACP Navigation Regulations, with detailed information reaching Marine Traffic Control not less than 96 hours before arrival and bulk dangerous cargo reported through VUMPA. The Authority then assigns a single Precaution Designator per vessel, set by the most restrictive packaged cargo, bulk cargo, empty tank or slop tank aboard, and that designator drives the restrictions applied in canal waters.

Vessels carrying Precaution Designators 1 to 6 display a signal. Designators 1, 3, 4 and 5, covering flammables and explosives, display flag B (Bravo) by day and a red light by night; designators 2 and 6, covering toxic or radioactive materials, display flag T (Tango). Designator N covers ACP vessels, private yachts, commercial towboats and fishing vessels under 38 m. Failure to provide the required information yields an H, or HOLD: the vessel may not transit, dock or enter the Cristobal Inner Anchorage. Hazardous waste under the Basel Convention must be reported by technical name, UN number and IMO class and division, with IMDG Code packaging and stowage certification.

Gas carrier transits are managed through the booking system rather than through a separate operational regime. A maximum of two slots per day may be allocated to LNG vessels through the normal booking process, LNG takes priority in the Period 1.a allocation order where slots remain, and the required arrival time for a NeoPanamax LNG carrier is 0200 on the day of transit. Daylight-only and encounter restrictions on LNG carriers were lifted with effect from 1 October 2018.

Ballast water, sewage and single-hull tankers

The canal’s discharge rules are absolute and they override the international baseline inside canal waters. N-1-2026 prohibits the discharge of ballast water, managed and unmanaged alike, from the southern ends of Miraflores and Cocoli locks to the northern ends of Gatun and Agua Clara locks, with discharge valves closed and padlocked at least two hours before the scheduled pilot time. Discharge of unmanaged ballast is also prohibited in the anchorages. Vessels loading cargo at the terminals must be fitted with an approved and operational ballast water management system or they may not discharge ballast at all.

There is no D-2 carve-out. A ship fully compliant with the Ballast Water Management Convention still may not discharge between the locks, which is a clean example of a canal authority imposing a stricter regional overlay on an IMO baseline. All ACP water bodies are likewise no-discharge zones for sewage, treated or untreated, because Gatun Lake is a drinking water intake; sewage valves are closed and padlocked from entry to the anchorage until departure. The outer boundaries of canal waters are the anchorage areas shown on charts DMA 21603 for the Pacific and DMA 26068 for the Atlantic.

Single-hull oil tankers carrying oil, as defined in MARPOL Annex I Regulation 1, are prohibited from transiting. The local trade of oil in Panama Canal waters, including bunkering by single-hull tanker, is likewise prohibited. Tankers below 5,000 dwt with single sides and a double bottom may make local calls to oil terminals only, on demonstrated compliance with MARPOL Annex I Regulation 19.6. Canal waters are not an emission control area, so the ECA fuel sulfur limits do not apply there; the global limit under MARPOL Annex VI does.

Traffic, revenue and the commercial consequences

The Panama Canal carried 13,404 transits and 489.2 million PC/UMS tons in FY2025, earning total revenue of B/.5.705 billion and a profit of B/.4.093 billion, and it transferred B/.2.965 billion to the Panamanian National Treasury. The balboa is pegged one to one with the US dollar. Cumulative contributions since the transfer of the canal to Panama reached B/.31.232 billion, the workforce stood at 9,014, and the ACP put its direct contribution to Panamanian GDP at 3.4 percent.

The traffic recovery from the drought was sharp. Transits rose 19.3 percent on FY2024 and tonnage 15.6 percent, and toll revenue rose 26.07 percent to B/.4,007.9 million. Tolls made up 70.3 percent of revenue, transit-related services 27.7 percent and other income 2.0 percent. Revenue has compounded at 10.0 percent a year since FY2019 while tonnage compounded at 0.7 percent, which is a pricing story rather than a volume story and is the clearest single statement of what the 2022 restructure did.

Segments, routes and commodities

Dry bulk and tankers drove the FY2025 recovery, adding 952 and 432 transits respectively over FY2024, with LPG up 244 and general cargo up 176. LNG went the other way, falling by 54 transits to 61, against 115 in FY2024 and 326 in FY2023, a decline of about 81 percent in two years. Container traffic, at roughly 2,893 transits, is the largest single segment by count and the most valuable by toll.

The ACP describes a network of more than 180 maritime routes serving 1,920 ports in 170 countries, and states that approximately 69.9 percent of canal cargo has a United States origin or destination, mainly East Coast and Gulf ports. Principal routes by tonnage are United States East Coast to Asia, United States East Coast to the west coast of South America, the west coast of South America to Europe, South American intercoastal, and the east coast of South America to Asia. The United States led origin and destination tonnage in FY2025 at 183.4 million long tons, followed by China at 53.5 million and Japan at 34.5 million. Crude petroleum, petroleum products and grain are the three largest commodity flows.

What canal risk does to a fixture

Canal cost and canal delay now fall in places the standard forms did not anticipate. Under a voyage charter , canal dues are a voyage expense borne by the owner, and waiting at a canal anchorage is ordinarily part of the voyage rather than laytime , because laytime runs at the loading or discharging port after a valid notice of readiness . Under a time charter the charterer bears canal costs as a voyage expense and the ship stays on hire in the queue, because queueing is not an off-hire event under the standard forms. The same delay therefore lands on opposite parties depending on the form, and neither outcome follows from anything the canal does.

The reservation fee, an auction bid and the Fresh Water Charge sit awkwardly in that framework. None is a conventional canal due, the sums involved can exceed the freight on a short voyage, and the printed clauses were drafted when a slot was a formality rather than a six-figure auction lot. The practical answer is to allocate them expressly in the fixture through a canal transit clause . Queue time also has a compliance cost that did not exist a decade ago: days spent at anchor burn fuel and produce no transport work, which loads a ship’s annual carbon intensity rating without moving any cargo.

Panama or Suez, and the alternatives when neither works

The canal competes on transit time, and on the ACP’s own comparison for a United States East Coast to Asia routing the alternatives run 26 days via Panama, 33 days via Suez, 37 days via the Cape of Good Hope and 43 days via Cape Horn . The genuinely contestable lanes are narrow: Asia to the United States East Coast and Gulf, where the two canals compete directly, and parts of the west coast South America trades, where Panama has no real rival. Asia to Europe is a Suez lane and has never been a Panama lane.

Distance savings are route specific. The ACP gives about 4,800 km saved on a United States east coast to Japan coal voyage and about 8,000 km on an Ecuador to Europe banana voyage. A canal saving quoted without naming the trade is not a usable number, which is why this article gives none.

The two waterways fail in different ways, and that is the practically important point. Panama is constrained by rainfall and lock geometry, and its failures are gradual, announced weeks ahead by advisory, and priced through the auction. Suez is constrained by geopolitics and channel width, and its failures are abrupt: the Ever Given grounding closed it outright in March 2021, and the Red Sea attacks from late 2023 pushed most container traffic onto the Cape of Good Hope without any change to the canal itself. A shipper hedging canal risk is hedging two uncorrelated exposures, which is why the 2023 and 2024 overlap of Panama drought and Red Sea diversion was so disruptive: both principal east-west routes degraded at once.

Comparison compiled by Shipping-Wiki.com from the canal authorities’ published transit rules and tariffs. The transit-day figures above are the ACP’s own.

The United States intermodal land bridge is the non-maritime substitute, moving boxes from West Coast ports by rail to eastern markets. It competes on time when the canal is constrained and loses on cost when it is not. The wider taxonomy of canals against straits, and the governance difference between a tolled canal and a strait governed under UNCLOS Part III, is in the canals and straits article; the Strait of Malacca and the Kiel Canal are treated separately.

History in brief

The canal was attempted by France, completed by the United States and has been operated by Panama since 1999. The treaty sequence is covered in full in the Panama Canal Treaties of 1977 article, and this section carries only the chronology a reader needs to place the engineering.

The French attempt

The Compagnie Universelle du Canal Interoceanique de Panama was organized on 17 August 1879 under Ferdinand de Lesseps, who had completed Suez in 1869, and work began on 12 March 1881. The plan was a sea-level canal on the Suez model, which underestimated both the Continental Divide and the Chagres River. The Culebra Cut was inaugurated on 20 January 1882 and its saturated spoil refused to hold its slopes. The company conceded a lock design on 15 January 1888, shareholders voted to dissolve in January 1889, and all activity ceased by 15 May 1889.

The peak French workforce exceeded 19,000 in 1884, largely West Indian and chiefly Jamaican, and by late July 1885 about one tenth of the estimated excavation was complete. Yellow fever and malaria killed an unrecorded number: the ACP states plainly that much of the French death toll was never recorded, and publishes no total. The Compagnie Nouvelle du Canal de Panama was organized effective 20 October 1894 to preserve the work pending a sale.

United States construction and the 1914 opening

The United States acquired the concession through the Hay-Bunau-Varilla Treaty of 18 November 1903, ratified by the United States on 23 February 1904, with Panama receiving USD 10 million. Construction dates from 4 May 1904, when Lieutenant Mark Brooke received the keys to the storehouses and Ancon Hospital. The total United States cost was about USD 375 million, inclusive of the USD 10 million paid to Panama and the USD 40 million paid to the French company, with fortifications a further USD 12 million. Hospital records give 5,609 deaths from disease and accidents in the American period.

The first complete transit by a self-propelled ocean-going vessel was made by the Alexandre La Valley, an old French crane boat, on 7 January 1914, through the Pacific locks. The official opening to international trade came on 15 August 1914, when the SS Ancon transited with about 200 aboard including the President of Panama, Belisario Porras.

From the 1977 treaties to the expansion

Both 1977 treaties were signed on 7 September 1977 and entered into force on 1 October 1979, on which date the Canal Zone ceased to exist. The United States Senate gave its advice and consent to the Neutrality Treaty on 16 March 1978 and to the Panama Canal Treaty on 18 April 1978, each by 68 votes to 32, one more than the 67 required. The Panama Canal Treaty terminated by its own terms at noon, Panama time, on 31 December 1999.

Panamanians approved the canal expansion by referendum on 22 October 2006, with the Electoral Tribunal recording turnout of 43.32 percent and a yes vote of 76.83 percent of ballots cast. Construction began in 2007 at a budget of USD 5.25 billion, executed by the Grupo Unidos por el Canal consortium, whose Italian member was Impregilo at contract award and is now part of Webuild. More than 150 million m3 was excavated. The expanded locks opened on 26 June 2016, and the inaugural transit was made by the COSCO Shipping Panama, ex-Andronikos, a 9,472 TEU container ship of 299.98 m by 48.25 m. The first LPG carrier followed on 27 June, the first vehicle carrier on 6 July, and the first LNG carrier, the Maran Gas Apollonia of 289 m by 45 m, on 25 July 2016.

Limitations

Every dimensional, tariff and capacity figure in this article is a dated statement of an operational rule that the Panama Canal Authority can change by notice, and several were changing while it was written. The draft limits are the clearest case: the published maxima of 12.04 m and 15.24 m TFW are conditional on Gatun Lake levels of 24.01 m and 25.91 m respectively, restrictions were in force through the second half of 2026, and the authorized draft on any given date comes from the current Advisory to Shipping and from nowhere else. The slot counts in the 2026 section were superseded once during drafting and should be assumed superseded again.

Tariff figures are given as they stand in the February 2026 consolidated tariff, whose item 1010 rows still carry 2023 to 2025 effective dates. They are not a quotation. A toll depends on admeasured PC/UMS or TEU allowance, the toll-assessment size category, the locks used, the ballast concession where it applies, and a Fresh Water Charge that varies with the lake level recorded at 1200 the day before transit, so only the Authority’s own assessment is authoritative.

Three classes of figure are deliberately absent. Auction clearing prices are press-reported rather than published, because the ACP does not release individual auction results, and they are attributed as such wherever they appear. Per-segment transit counts for FY2025 other than the published totals and the year-on-year changes are read from graphs in the Annual Report rather than from tables. And several widely repeated statistics have been left out entirely rather than hedged, including a 6 percent share of world trade, a 5 percent share of global LNG shipments, a 40 percent share of United States container traffic from Asia, and a 12,875 km Cape Horn voyage length: none could be traced to a primary source, and the ACP’s own published figure is nearly 3 percent of global maritime trade. The French-period mortality range often quoted is likewise omitted, because the ACP states the toll was never fully recorded.

Related Articles

• Suez Canal : the sea-level alternative, its SCNT dues basis and its very different failure mode.
• Canals and straits : the taxonomy, the comparative limits and the canal against strait governance contrast.
• Panama Canal Treaties of 1977 : the treaty sequence, the sovereignty analysis and the 1999 handover.
• Panama Canal Universal Measurement System : the admeasurement formula and the certificate.
• Suez Canal Net Tonnage : the competing canal tonnage, for the contrast with PC/UMS.
• Container ship size classes : the Panamax, NeoPanamax and ULCV ladder the lock geometry produced.
• Bulk carrier size classes : the Panamax bulker and why Capesize ore voyages still round the capes.
• Tanker size classes : where the canal sits in the crude and product tanker ladder.
• LNG carrier : the Q-Flex and Q-Max distinction that the 2018 beam increase turned on.
• Cape of Good Hope route : the principal fallback when a canal is constrained or avoided.
• Red Sea crisis and Cape diversions : the Suez-side disruption that overlapped the Panama drought.
• Strait of Malacca : the Asia-side chokepoint on the competing routings.
• Kiel Canal : the other major lock canal, for the comparison of tolls and dimensional limits.
• Ballast Water Management Convention : the IMO baseline the canal’s flat discharge prohibition overrides.
• MARPOL Convention : Annex I Regulation 1 and Regulation 19.6, which the single-hull prohibition turns on.
• Tonnage measurement : ITC-69, and why PC/UMS is not gross tonnage.
• Pilotage operations : compulsory pilotage regimes, of which the ACP’s is the strongest form.
• Laytime and demurrage : how canal waiting time is treated, and how it is not.