A Vessel is a ship engaged in commercial maritime transport. In containerized international trade, vessels are operated by Vessel-Operating Common Carriers (VOCCs) — Maersk, MSC, CMA CGM, Hapag-Lloyd, ONE, Evergreen, COSCO, and others — and are typically chartered or owned outright by the carrier.
Every vessel is identified by:
- IMO number — a permanent 7-digit identifier from the International Maritime Organization, never reassigned
- Vessel name — assigned by the operator and can be changed
- Call sign — radio identifier under ITU rules
- Flag state — country of registry; common open-registry flags include Panama, Liberia, and the Marshall Islands
Each commercial voyage has a voyage number combining vessel name, sailing direction, and sequence (e.g., "MAERSK ESSEX 412W" — westbound voyage 412). The voyage number is referenced on every bill of lading, in every AMS filing, and in every ISF record.
Container vessel categories by capacity:
- Feeder — under 3,000 TEU; serves smaller and regional ports
- Panamax — 3,000–5,000 TEU; sized for the old Panama Canal locks
- New Panamax / Neopanamax — 5,000–14,000 TEU; sized for the 2016 Panama Canal expansion
- ULCS (Ultra Large Container Ship) — 14,000+ TEU; largest ships in service today exceed 24,000 TEU
Vessel arrival schedules — Estimated Time of Arrival (ETA) — drive the entire downstream supply chain, including free time, demurrage, trucking dispatch, and warehouse receiving.