The single biggest contributor being the Humber lifeboat City of Bradford II ON 709, which in twenty five years at the station launched on service 228 times, saving 305 lives.

The 45ft 6in Watsons differed from the previous 45ft type in having flush decks with no end boxes.

The aft cockpit had a shelter ahead of it covering the engine room access hatch.

The fourth in the series (ON 701) had a unique twin engine, single screw layout which was not repeated.

The drop keel fitted to the single engine boats was deleted from the twins and eventually the auxiliary sailing rig was dispensed with on the twins in the light of operational experience.