Two of the World's Shipping Shortcuts Were Already Squeezed. Panama Just Started Rationing the Third.

The advisory splits the cut into two phases. Phase one, for reservation dates from 4 September, sets nine daily slots in the larger Neopanamax locks and 25 in the older Panamax locks — 34 in total, against the 10 and 26 that had been on offer. Phase two, from 15 September, holds Neopanamax at nine and drops Panamax to 23 (five regular and 18 'super'), for 32. Draft has been ratcheting down all summer in the Neopanamax locks: 49.5 feet on 3 July, 49 feet on 24 July, 48.5 feet on 15 August, 48 feet on 26 August and 47.5 feet thereafter — a limit whose start date has itself moved, from 3 September to 1 October. The Authority has been running water-saving measures since December 2025 — cross-filling lock chambers, using short chambers, sending vessels through together, and suspending hydraulic assistance where it can. Those measures are why, in May, it told Reuters it saw no need to limit crossings this year. Al Jazeera puts the canal's normal ceiling at roughly 40 vessels a day and its average since June at 35; gCaptain reports 6,288 transits in the first half of fiscal 2026, with March averaging 37 a day and some days above 40. Whichever baseline you take, the September numbers are a cut, and the Authority is explicit that it may cut further: officials warn the 2026-27 El Niño could deepen the deficit through the January-April dry season.

The mechanism is not complicated and not disputed. Gatún Lake is both the canal's water supply and the drinking-water source for Panama City and Colón; a lock transit consumes fresh water that only rain replaces. El Niño suppresses rainfall over the isthmus, so a strong El Niño is a direct constraint on how many ships can be lifted over Panama. The 2023-24 event is the reference case: Woodwell Climate's analysis recorded passages capped at 24 a day until April 2024 against a normal 38, with transits about 30% below usual by the end of 2023, and attributed the drought to El Niño compounded by climate change. What is different in 2026 is the sequencing. In 2023 the restrictions followed the shortfall; here the Authority is rationing on a forecast, having spent the intervening two years on conservation measures and having publicly expected them to hold. Confirmed rather than likely: the Authority states the hydrological cause in its own advisory, the deficit figures are its own, and no source contests the physical mechanism.

The Authority's booking system ranks vessels into priority groups — LNG and LPG carriers; dry bulk and general cargo; containerships and vehicle carriers; chemical and product tankers — with full containerships allocated on TEU capacity. That structure means the cost of scarcity is not distributed evenly: a large containership on a booked slot sails on schedule, while an unbooked vessel either bids into a thin auction or waits. The auction record set on 14 August is the clearest single number in this story, and it was set by a gas carrier — for LNG and LPG, where cargo value per voyage is high and delivery windows are contractual, an eight-figure detour or a missed window can cost more than the slot. The second beneficiary is the rerouting economy. Lloyd's List Intelligence records Asia-Europe volumes drifting back to Suez — more than 30% of what Maersk had been sending around the Cape of Good Hope has returned — and every ship that leaves the Panama queue for a longer route consumes more ship-days, which is a benefit to owners in a market priced on tonne-miles. Likely rather than confirmed: the auction figures and the priority structure are documented, but 'who nets out ahead' across carriers and shipowners is an inference from how the mechanism distributes cost, not something any source has totalled.

The canal handles about 5% of global maritime trade, and its principal lanes — the US East Coast to East Asia first among them — have no short substitute. Normally a Panama constraint is absorbed by rerouting: ships go the long way, freight rates rise a little, and the system copes. What makes 2026 different is that the rerouting capacity has already been spent. Lloyd's List Intelligence's 20 August brief counts nearly 1,090 Suez transits over four weeks, 88.6m deadweight tonnes, and puts that at 41% below pre-crisis levels; Bab el-Mandeb traffic fell from an average of 296 weekly transits to 265 after the Houthi blockade of 20 July. Carriers are only tentatively returning. So cargo squeezed out of Panama meets alternatives that are themselves rationed by risk rather than by water — and the cost shows up as surcharges, which Supply Chain Dive confirms MSC and CMA CGM have already implemented or updated. Likely rather than confirmed on the consumer end: the surcharges, the transit deficits and the auction prices are all documented, but no source yet quantifies what share of them reaches a shelf price, and claiming a number for that would be inventing one.