Sealift

Sealift is the transportation of equipment, supplies, and personnel by sea, typically using merchant or naval auxiliary ships. It is a primary modality for moving bulk cargo, heavy equipment, and large quantities of materiel to domestic and international theaters, and it operates alongside airlift as part of comprehensive military logistics.

Sealift encompasses strategic lift, which focuses on deploying and sustaining forces over long distances, often across oceans, and tactical lift, which moves materiel within a theater from ports to forward areas. Vessels include container ships, roll-on/roll-off ships, breakbulk carriers, and prepositioned ships. The operation often uses a combination of chartered commercial tonnage and government-owned ships operated by civilian crews under military command, notably in the United States with the Military Sealift Command.

Prepositioning programs place ships loaded with equipment at strategic locations to reduce transit times during crisis. In addition to military uses, sealift is critical for humanitarian relief and disaster response, enabling rapid delivery of relief supplies to affected regions.

History: The concept matured during the 20th century as sea lift became essential for large-scale deployments. In the United States, the Military Sealift Command and allied navies built fleets and support arrangements to project power and sustain operations overseas, particularly during Cold War and post-Cold War periods.

Advantages and challenges: sealift is cost-effective for heavy and bulk cargo but slower than airlift and susceptible to disruption by weather, port congestion, or enemy interdiction. Modern sealift relies on intermodal connectivity, prepositioned stocks, and secure shipping lanes.