On July 30, 2023, the Panama Canal Authority (Autoridad del Canal de Panamá, ACP) issued an advisory reducing the daily transit allocation through the canal from the normal 36-38 vessels per day to 32. The reason was hydrological: Gatun Lake, the artificial reservoir that feeds water into the canal's locks every time a vessel transits, was at unusually low levels following an extended dry season exacerbated by an emerging El Niño. By October 2023 the daily allocation had been cut to 25; by November to 22; and by February 2024 the cap reached its low of 18 vessels per day — half the normal throughput, the lowest sustained operating level in the canal's modern operating history outside of major maintenance windows.

The cap forced shipping operators into one of three choices: pay a substantial premium in the canal's slot-auction mechanism (winning bids exceeded $4 million for a single transit during the worst weeks); wait days or weeks at anchor for a slot; or re-route around Cape Horn or the Suez Canal at substantial additional fuel and time cost.