A stern mounted vertically adjustable propeller and rudder marine drive. The aft end of a propeller shaft (24), the propeller (38), the rudder (60) and a skeg (42) are vertically movable to adjust a boat's draft for use in the water and when trailering. A stern underwater slot in the boat hull is shaped to enhance water flow and accommodates the propeller shaft which is driven by an inboard engine. As the propeller shaft passes through the hull slot it engages a flexible water seal mechanism (32) which self adjusts or maintains itself in various up and downward positions; its pivotal point is common with the centerline pivotal point of a universal joint (20), which is attached to the drive shaft and connected to the transmission of an inboard engine.