The Volvo Penta Aquamatic 280 Stern Drive

The stern drive is a well known propulsion unit which has been successful due to its high performance and combination of features.

The drive unit contains channels for exhaust and cooling water, it must support the propeller and associated gears, bearings etc and at the same time have low underwater drag. Furthermore, the boat is manoeuvered by components of housing hydrodynamic lift and propeller thrust.

The various demands, sometimes in conflict with each other, make the design of a stern drive an “optimum compromise”.