As with the Volvo Penta IPS, the propellers are fixed in a horizontal plane, efficiently applying thrust forward — not upward thrust as standard inboards do. Each drive turns independently 60 degrees to give the control we experienced. Propeller drives fit in hull tunnels to reduce draft. Unlike on the IPS system, the props are turned backward; MerCruiser claims the setup offers more protection against impact than the competition's setup. Trim tabs are integrated into the Zeus system, and they decrease bow rise.