This article includes a
A rescue lifeboat is a
There are generally three types of boat, in-land (used on lakes and rivers), in-shore (used closer to shore) and off-shore (into deeper waters and further out to sea). A rescue lifeboat is a boat designed with specialised features for searching for, rescuing and saving the lives of people in peril at sea or in estuaries.
A vessel and her crew can be used for operation out to 20 nautical miles (37 km) away from a place of safe refuge, remaining at or on the scene to search for several hours, with fuel reserves sufficient for returning; operating in up to gale force sea conditions; in daylight, fog and darkness. A smaller IRB inshore rescue boat / ILB inshore life boat and her crew would not be able to withstand (or even survive) these conditions for long.
In countries such as Canada and the United States, the term 'motor lifeboat', or its US military acronym MLB, is used to designate shore-based rescue lifeboats which are generally manned by full-time coast guard service personnel. On standby rather than on patrol mode these vessels are ready for service rather like a crew of fire fighters standing by for an alert. In Canada, some lifeboats are 'co-crewed', meaning that the operator and engineer are full-time personnel while the crew members are trained volunteers.