Domestic commercial vessels must have and display a unique identifier.
A unique identifier is a number that stays with the vessel for its entire life, even if the vessel changes ownership. A vessel may need to be identified:
- for search and rescue purposes
- if it has been lost or stolen
- if it is being operated dangerously or illegally
- if it is being surveyed.
Some vessels are exempt from the requirement to have a unique identifier, or from displaying it or both.
