A refrigerated container or cargo space maintaining a controlled temperature for perishable goods during transport.
The chief mate or cargo officer monitors reefer temperatures throughout the voyage, with readings logged at regular intervals—often every four to six hours—and reported to charterers and receivers. On container ships, reefer containers receive electrical power from dedicated deck sockets, and the number of plugs fitted limits the total reefer capacity. Any temperature excursion must be documented and investigated immediately: spoiled perishable cargo is a significant liability and may result in cargo claims under the Hague-Visby Rules. The OOW on watch should check the reefer monitoring system alarms at every watch handover.
Source: Industry usage
Editorial confidence: how we grade.