The Merchant Navy is the common term for the commercial shipping industry. Roles within the Merchant Navy vary depending on a number of factors, including size and type of vessel. The range of vessels includes passenger ferries, container ships, tankers, small tugs, and cruise ship. Some vessels have a large number of officers and ratings, whilst others have a very small number of officers and ratings. This affects the breadth of responsibilities and seniority of those on board. Furthermore, there are fewer statutory certification requirements for officers working on small vessels and on vessels working in the near coastal area.