[1] Based on an American design, 22 saw operational service between 1964 and 1999 at the RNLI's stations around the coast of the United Kingdom and Ireland.

After being superseded by faster boats in the 1990s, many were sold for further use with lifeboat services abroad, notably in Australia and New Zealand.

In the 1960s the RNLI's fleet consisted of motor lifeboats of limited speed due to the shape of their hulls.

[2] One was built for the RNLI by the USCG in Curtis Bay Coast Guard Yard, Maryland,[3] and this was put through extensive trials and proved capable of operating in restricted spaces, even though the propellers lacked the usual protection afforded to lifeboats.

The Groves & Guttridge built boats of 1974/5 had more powerful 260 bhp (190 kW) General Motors V-8 engines which they retained throughout their service life.