Basically there are no universally relevant definitions of ship types, particular descriptions & names are used within IMO treaties & the conventions. The following is the list ship types defined in several IMO instruments:
- A passenger ship is a type of ship which can carries more than (>)12 passengers. (SOLAS I/2)
- A fishing vessel is a type of vessel normally used for catching fish, seals, whales, walrus or other living creatures of the sea. (SOLAS I/2)
- Fishing vessel is a type of vessel used commercially for catching fish, whales, walrus, seals or other living creatures of the sea. (SFV 1993 article 2)
- A nuclear ship is a type of ship which contains a nuclear power plant. (SOLAS I/2)
- Bulk carrier means a ship which is built normally with single deck, top side tanks & hopper side tanks in cargo spaces, & is used mainly to carry dry cargo in bulk, & comprise such types as ore carriers & combination carriers. (SOLAS IX/1.6)
- Bulk carrier is a type of ship which is used mainly to carry dry cargo in bulk, comprise such types as ore carriers & combination carriers. (SOLAS XII/1.1)
- Oil tanker means a ship built primarily to carry oil in bulk in its cargo spaces & comprise combination carriers, any “NLS tanker” as specified in Annex II of the present Convention & any gas carrier as specified in regulation 3.20 of chapter II-1 of SOLAS 74, when carrying a cargo of oil in bulk. (MARPOL Annex I reg. 1.5)
- General cargo ship: A ship with a single-deck hull or multi-deck constructed mainly for the transportation of general cargo. (MEPC.1/Circ.681 Annex)
- High-speed craft is a craft able to travel at the high speed. (SOLAS X/1.2, HSC Code 2000 para 1.4.30)
- MODU(Mobile offshore drilling unit) is a type of vessel involved in the drilling operations for the exploration of resources under the sea bed such as liquid or gaseous hydrocarbons, sulphur or salt. (SOLAS IX/1, MODU Code 2009 para 1.3.40)
- Special purpose ship (SPS) means a mechanically self-propelled ship which by reason of its function carries on board more than 12 special personnel. (SPS Code para 1.3.12)
