IMO SPS Code of Safety for Special Purpose Ships 2008 Edition IA820E
The Code of Safety for Special Purpose Ships has been developed to provide an international standard for special purpose ships of new construction, the application of which will facilitate operation of such ships and result in a level of safety for the ships and their personnel equivalent to that required by the SOLAS Convention.
For the purpose of this Code, a special purpose ship is a ship of not less than 500 gross tonnage which carries more than 12 special personnel, i.e. person who are specially needed for the particular operational duties of the ship and are carried in addition to those persons required for the normal navigation, engineering and maintenance of the ship or engaged to provide services for the persons carried on board.
Because special personnel are expected to be able bodied with a fair knowledge of the layout of the ship and have received some training in safety procedures and the handling of the ship's safety equipment , the special purpose ships on which they are carried need not be considered or treated as passenger ships.
Special purpose ships carry special personnel who may include; but are not limited to, scientists, technicians, personnel who process the catch of fish on factory ships, personnel engaged in maritime training, salvage or cable laying personnel.