I was lucky enough to hop aboard the Bernard Matthews II, our local lifeboat here in Caister. What an impressive machine it is.
It has two 450hp engines which when not in service are kept warm by electric heaters to limit wear caused by operating when cold. It can operate at speeds of 37 knots (43mph) for a duration of 6 hours and can stop from full speed within its own length of 11 meters. It works by water propulsion instead of propellors so can operate in shallow water (waist depth). It has a crew of 4 and I understand is on average in the water within 7 minutes of pager alert. It has 3 fuel tanks, stern, center and bow. Fuel can be pumped between them as required. In calm water fuel is kept to the stern to enable the now to lift so the craft and plane across the water. In rough seas the opposite to help keep the bow down.
Caister Lifeboat is a charity and manned by volunteers and not run by the RNLI.