The Surprise 25 is a recreational
keelboat, built predominantly of
fibreglass. The hull is solid fibreglass and the deck is
balsa-cored fibreglass. It has a 7/8
fractional sloop rig with
aluminum spars, a deck-stepped mast, wire
standing rigging and a single set of swept spreaders. The hull has a
raked stem, a slightly
reverse transom with an inset, an internally mounted spade-type
rudder controlled by a
tiller with a "D"-handle extension. It was delivered with a choice of a fixed fin
keel, twin asymmetrical keels with bulb weights, or a
swing keel. It displaces and carries of
cast iron ballast. The fin keel-equipped version of the boat has a draft of , the twin keel-equipped version of the boat has a draft of , while the swing keel-equipped version has a draft of with the keel extended and with it retracted, allowing ground transportation on a
trailer. The boat is normally fitted with a small
outboard motor of up to for docking and manoeuvring. The design has sleeping accommodation for four people, with a "V"-berth in the bow cabin and two straight settees in the main cabin. The main cabin headroom is . For sailing downwind the design may be equipped with a symmetrical
spinnaker of . It has a
hull speed of . ==Operational history==