Mercury 100HP CT 4-StrokeHeavier boats used for pleasure, fishing or commercial applications often sit high on the water and are hydro dynamically different from other lighter boats. To address those differences and in response to additional challenges, Mercury developed its Command Thrust family of outboards. Command Thrust gearcase Available for the 90 and 115hp outboards, the Command Thrust gearcase is designed to turn larger props. It helps get heavy boats on plane more