Following a visit in the early sixties to lifeboat societies in the Netherlands and West Germany, which successfully employed cruising lifeboats, the RNLI's Management Committee decided to sanction the construction of two such boats for RNLI service.

The Clyde-class cruising lifeboat was the largest ever built for the RNLI and the first to have a steel hull.

As crews were intended to live on board, berths and messing facilities were provided.

The boats were powered by two 230 brake horsepower (170 kW) Gardner 8L3B 8-cylinder diesel engines driving twin screws.

This was based on the Oakley hull design, but featured a completely redesigned superstructure resembling an overgrown Arun.