Special purpose vessels are designed to perform specific work or tasks. Typically, this type of vessels includes tugboats, icebreakers, rescue ships, firefighters, research, expeditionary, oil spill response and other vessels. Usually, special personnel are carried on board special purpose ships.

"Special personnel" means all persons who are not passengers or members of the crew and who are carried on board in connection with the special purpose of that ship or because of special work being carried out aboard that ship.