I have tried to find out what the rules are regarding how fast you can go on Lake Washington. All I have found so far is what limits there are when you are close to shore. Whether this means you can go as fast as you like while out in the open or not I don’t know. We do see plenty of people getting some speed up when they are out on the water. Whether it is speedboats of ski boats pulling someone behind them, they look nice and dramatic when they are up on the plane and moving.