Systems and methods use cyclical propellers with dynamic blade angle control to extract power from waves. A control system for such implementations can adapt pitching schedules for the blades of the cyclical propellers for efficient energy extraction and/or to control reactive forces. The cyclical propellers may be installed on the floor of a body of water or other liquid, on a submarine, or on a surface float, and blades may extend vertically or horizontally depending on the character of the waves. Several cyclical propellers can be combined into a single unit operated to minimize reactive forces and torques, to propel the unit horizontally or vertically, and/or to stabilize the unit. Such units can be installed with minimal or no moorings.