Disclosed is an apparatus that floats at the surface of a body of water over which waves pass. Passing waves cause a nominally vertical axis of the apparatus to tilt away from an axis normal to the resting surface of the body of water. Tilting of sufficient magnitude and duration allows a fluid to flow through a channel that in an un-tilted apparatus would require the gravitational potential energy of the fluid to increase (i.e., to flow uphill), but, because of the tilt allows the fluid to flow through the channel in a downhill direction. Flowing water is trapped at a plurality of levels which in an un-tilted apparatus are higher than the respective levels from which the fluid has flowed. A subsequent tilt of the apparatus in a sufficiently different direction, and of a sufficient magnitude and duration, causes the trapped water to flow to new, yet higher levels. Successive wave-driven tilts of the apparatus incrementally raise water to a height and/or head from which a portion of its gravitational potential energy can be released, and/or converted to electrical power, by causing the water to return to a lower level by flowing through a water turbine thereby energizing an operationally connected generator, or through some other apparatus that performs a useful function when supplied with a flow of high-pressure water.