Pod Drive Engines

Since 2004, engine makers have been building a new form of marine propulsion called Pod Drives. These feature inboard engines—usually diesel—with a transmission inside the hull behind the engine. The transmission uses a downward oriented shaft that goes through the pod housing into the water to the gear case tucked up in front of the transom. The pod drive pivots to direct thrust. These engine systems offer more thrust per horsepower because they are perfectly aligned to the keel of the boat, making all force go in line with the boat’s motion. By contrast, inboard boats have a shaft that goes through the hull at an angle that turns the propeller downward by several degrees. Some of the thrust is lost to this downward orientation. Pod drives incorporate special steering and throttle systems that are entirely electronic. They are integrated with GPS systems on board and auto pilots for easy course plotting. Station keeping is a feature that allows the boat to maintain its position—say while you fit fenders and lines to moor the boat—until you return to the helm. The engine systems are more expensive, but save considerable space onboard, adding the possibility of an additional cabin or entertainment room. They are designed to shear off on impact in a grounding, sparing much damage to the hull and making getting back underway as easy as possible.