Mercury Racing ProMax Deuce High

The Deuce High was packed full of the latest tech.

Testing the Deuce High at Lake X is (left) Mike Mullins of Mirage Boats and the late Charles Alexander, a brilliant engineer who joined Mercury in 1953 and served as company president from 1977 to 1985.Courtesy Mercury Racing

The Mercury Racing ProMax 200 Deuce High outboard was a full-out engineering project that combined the fuel injected 200-horsepower 2.5-liter V-6 ProMax EFI powerhead and an advanced propulsion system. The mid section and gearcase were designed from a potpourri of sterndrive and outboard hydrodynamic engineering concepts and a very clever prop clutching device.

The most unique of its design innovations was its two-speed automatic gearcase. The engine drove two, contra-rotating props, like the MerCruiser Bravo Three sterndrive. Unlike the Bravo Three, the props were sequentially shifting: On initial acceleration, one prop would free-wheel while the other spooled up quickly. A computer-controlled hydraulic clutch system automatically engaged the second prop when the engine reached a pre-set torque. This resulted in outstanding hole-shot acceleration.

Mercury Racing ProMax 200 Deuce High outboard was a successful engineering project, but too expensive for the marketplace.Courtesy Mercury Racing

Water pickups were built into a removable skeg. The fully surfacing gearcase was designed to run with the full torpedo above the water. The water running beneath the propeller hubs and torpedo improved propeller efficiency and eliminated torpedo drag. The contra-rotating, fully surfacing props delivered unsurpassed boat speed and very good fuel efficiency. This design also improved handling and stability because steering loads were neutrally balanced at all planing speeds. The boat was amazing crossing wakes or waves at odd angles – it just tracked like an arrow and was much easier to drive than a typical high-performance bass boat. Testing the Deuce High 200 at Lake X in Florida on a Mirage River Racer tunnel hull reportedly produced top speeds of more than 130 mph.

Unfortunately, Mercury Racing couldn’t sell the Deuce High at the price of an arrow; it would need to be priced more like a cruise missile. The expensive hardware – two exotic stainless steel props, the stainless steel girdle/water pickup and the prop shaft/clutch mechanism – cost too much for the bass market (MSRP was reported in some publications to be $16,500). Only two examples were assembled and the motor appeared only at the Mercury Dealer Meeting and at the IMTEC marine trade show in Chicago in October 1997.