I'm looking for some back-of-the-envelope calculations on an idea. Say there is a buoyant mass floating on the water. It is connected to a system which, when waves move the mass up and down, it pulls a string which turns a wheel of an electromagnetic generator (assume there is a mechanism which allows only pulling in one direction to spin the wheel). Assuming the wave height and frequency is known, and the mass of the object, how can the output power be calculated? I think the output power of the generator should be the torque multiplied by the angular speed, but I'm not sure if this is correct or how to complete the process. Also, how would the generator's efficiency affect the mathematics?