This sub-class includes: - sea freight water transport, whether scheduled or not; - transport by towing or pushing of barges, oil rigs etc.
This sub-class excludes: - storage of freight, see 521 (Warehousing and storage); - harbour operation and other auxiliary activities such as docking, pilotage, lighterage, vessel salvage, see 52221 (Operation of harbors); - cargo handling, see 52243 (Harbour cargo handling).