The 31 Grand Slam, however, was built on a conventional deep-V hull and she was powered by twin inboard engines. At first glance she appears to be a fairly standard open sport fisherman with a large fishing cockpit. A closer look reveals several interesting features. The helm seat, for example, can be converted into a leaning post. Engine access is good-a unique central service bay houses all the mechanical and electrical systems. The cockpit features modular tackle centers, rod holders and storage bins. For accommodations, there are four single berths below (the dinette seatbacks convert to single bunks) and a standup head with shower. Standard gas engines did not prove particularly popular with buyers. Early models with optional 250hp Cummins diesels cruise at 28 knots and reach 33 knots wide open. Cummins 300hp diesels (available after 1990) cruise at 30 knots and deliver 34-35 knots top. About 160 were built during her production run.