CAP3000's can handle larger waves, but if you have a strong wind (20kts +) and big waves then you might be able to land, but the problem is that you don't dare turn the plane broadside into the waves/ wind. You can sail backward, but if you are heavily loaded then I would recommend doing it with power on. It helps to keep the plane straight and prevents the heels from digging in backwards and flipping the plane. However, if the wind and waves are so bad that you have to employ this technique then you probably shouldn't be flying.
Carefully thinking ahead before the flight and planning your taxi and takeoff run and then doing the same with your landing location and taxi path will help you decide how much wind is acceptable. Pays to allow for a little more wind than forecasted at the other end. The pendulum effect of turning in high winds and big waves in open water is especially dangerous as it exposes the underside of the wing to the wind. No two situations are ever exactly the same so careful preflight planning, caution and working your way up to higher winds over time is the safest. Seems every experienced float pilot can recount play by play some wind situation that is still pretty vivid in their mind.