This matrix is a quick reference for crew-change planning. Whether you are joining a vessel for the first time or signing off at a foreign port, visa requirements depend on three key factors: the port country you are entering, your nationality, and how long you intend to stay ashore. The IMO Convention on Facilitation of International Maritime Traffic (FAL Convention) encourages member states to minimise documentation and formalities for seafarers, but it does not waive visa requirements — a seafarer may still need a national visa, a transit visa for an intermediate airport connection, or a specific crewmember visa category even in FAL Convention member states. Singapore and the UAE, for example, are major crew-change hubs with liberal visa policies for most nationalities, whereas the United States requires all non-VWP seafarers to hold a C-1/D crewmember visa applied for in advance regardless of FAL obligations.