Wave powered vessel propulsion

A couple of ideas:
1. A weight is hung on a shaft from the bottom of the vessel on a universal joint. Above the universal joint is a set of 4 pistons (front, back, left & right), also connected to the shaft. As the vessel rocks on the waves, the weight continues to hang down vertically, and the shaft moves in relation to the vessel. This causes the pistons to be moved in the cylinders. This movement pumps sea water in a controlled direction for propulsion, or through a turbine connected to a propeller (depends on pressure/flow matching).

2. Requires long rolling waves. A fixed shaft is rigidly connected to the bottom of the vessel. At the bottom of the shaft is a hydrofoil. When the vessel is riding up the wave, it's bow is inclined, and so is the hydrofoil. But the vessel is climbing, so the hydrofoil is raised through water while it is slightly pointed up, giving forwards thrust. Going down the wave will work in the opposite way. Sideways rocking would require a flexible, rubber-like, vertical hydrofoil. I think this might only be applied to forward motion only, and to be honest, I can't figure out if the vessel would finally just follow the motion of the wave.