15th Annual Great Lakes Grand Prix Offshore

The American Custom Marine with owner/throttleman Mike Knoblock and driver Matt Soper claimed victory at the 15th Annual Great Lakes Grand Prix Offshore race on August 4, 2024, in Michigan City, Indiana.

The 42-foot Fountain deep-V hull is powered by a pair of Mercury Dual Cal 1550/1350 inboard engines propelled through Arneson surface drives. The powerplants feature an advanced control system that enables the crew to switch engine power levels via an electronic key fob. Calibration provides maximum torque and efficiency and is designed to optimize the engine’s performance at each power level.

“The calm water on the Lake Michigan race course enabled us to reach a speed of 140 mph,” says Knoblock.

—Paul Kemiel