When can a vessel fly the local national flag?

A vessel can fly the local national flag after going through customs and immigration as this process signifies that the vessel has officially entered the territorial waters of that nation and is legally recognized within its jurisdiction. This protocol is essential for respecting the sovereignty of the country being visited and ensures that all customs regulations and entry requirements have been met.

The act of flying the national flag typically indicates that the vessel is now subject to the laws of that country, including maritime laws, and affords certain protections and responsibilities while operating within its waters. This is a formal acknowledgment of the vessel's presence and status in that nation. Observing customs and immigration protocols reflects maritime etiquette and respects the sovereignty of the host nation.

Flying the flag before leaving port does not appropriately signify entry into the new country; it may indicate a vessel is preparing to depart, which does not align with the customary onboard practice. While national holidays may involve additional ceremonial flag displays, it is not a requirement for the legal status of the vessel in the local waters. Lastly, while anchored in local waters, the national flag can be flown, but this is contingent upon the proper customs and immigration process being completed beforehand.