A wave energy converter includes a surface float including a non-axisymmetric profile, a reaction plate configured to be submerged below a water surface, and more than one flexible tether, each mechanically coupled to both the surface float and the reaction plate, the reaction plate having a moment of inertia in pitch and roll greater than a moment of inertia in pitch and roll of the surface float.

A device for generating electrical energy from mechanical motion includes a surface float and at least one force modifier disposed at least partially within the interior of the surface float, the force modifier to receive an input force at a pumping cylinder and apply a modified force to a generator through a driving cylinder. The pumping cylinder or the driving cylinder is a tandem cylinder.