Seamaster Ltd ceased trading 2 years after launching the Seamaster 820 but in that time nearly 100 were built. The boat was designed by Bob Hancock. The open plan cabin has 4 berths, and the cockpit has an open backed wheelhouse. The hull shape is a shallow V with a three quarter length keel. Several boatyards have used the deep hull wide beam design to produce their own versions. Carrington Marine built an 820 version and Boating Scene produced a Duchess 9mtr (a joint development with L.H.Jones). The Seamaster 28 is still in production with Viking boats and uses the 820 hull. There were various engines installed.