National Flags

Give the country, the size in feet and the number of flags; the IMPA code changes with the size. Choose the size to suit the mast, yard and halyard it will fly from.

Check whether the country you need uses a separate civil ensign. The usual rule for a courtesy flag is to fly the ensign the ship would fly if it were registered in that country, so a merchant ship generally flies the civil ensign. Some countries consider the national flag correct instead. Civil ensigns are in the neighbouring group.^[4]

For dependent territories, practice varies. For French dependencies the French tricolour is the correct courtesy flag, with any local flag flown only in addition. Order the territory’s flag only when the agent or the port asks for it.^[4]

Under UNCLOS, ships have the nationality of the state whose flag they are entitled to fly. A ship sails under one flag only, and may not change it during a voyage or in a port of call except on a real transfer of ownership or change of registry. A ship using two flags as it suits may be treated as a ship without nationality.^[1]

Flag-state law sets when the colours are shown. Under the UK Merchant Shipping Act 1995, for example, a British ship other than a fishing vessel must hoist the red ensign or other proper national colours on a signal from one of His Majesty’s ships and on entering or leaving any foreign port. Ships of 50 gross tonnage or more must also do so entering or leaving a British port.^[2]

Panama Canal rules require all vessels to display the Panamanian flag from dawn to 1800 hours in Canal waters, including anchorages; they may also fly their national and house flags. The Canal’s vessel-requirements notice explains the correct way up: the white quarter with the blue star at the top next to the pole, the blue quarter directly below it.^[3]

There is no international rule obliging a ship to fly a courtesy flag, but a number of states require it by local law in their waters.^[4]