Designed by RNLI Naval Architect James Barnett, the Surf-class was the smallest and lightest offshore motor lifeboat produced by the Institution.

The boats however, were only really suitable for inshore work in moderate conditions and they only had long service lives at two stations.

While this was a benefit in shallow waters, the cone powered boat was around 1 knot (2 km/h; 1 mph) slower than the screw version.

The second batch appeared in 1938 and had 3 inches (7.5 cm) more beam and were fitted with a shelter ahead of the (tiller) steering position.

All but one featured Hotchkiss cone propulsion, RNLB Kate Greatore (ON 816) was fitted with Gill water jets.