Mooring Strategies

Never assume your airplane is going to stay exactly where you put it while it's on the water. My plane is fairly secure at its specially built seaplane dock, which raises it out of the water and provides multiple solid tie downs. If it's anywhere else, I am never really at ease.
Strange docks are probably the worst. You never know how well anchored their cleats are going to be, or how rough the structure of the dock will be on the floats (be wary of objects below the surface that can jab at the sides of the floats). I am also nervous about other (especially pontoon type) boats that have roofs that can hit my wings. Boaters are not accustomed to other boats having a 12 foot overhang out to the sides. So I worry about these roofs denting my wings, ailerons, flaps etc.

Beaching is another matter. If the wind is blowing directly into the beach, you are in better shape but otherwise you need to check on the plane all the time. I had one instance this summer when I went back to the plane, and a pontoon boat was in the place I had beached my plane, and the boat was using my rope still tied to the tree that I had tied off to! My plane was nearby but loose, and fortunately the wind was keeping it at the beach. I can't imagine doing this to another boat. When we take the plane to lunch dinner in the plane, I usually check on it every 15-20 minutes.

During the drought of 2007, I had to leave the plane at the beach for nearly 8 months, while the water kept going down and then while the water came back up. I had to move the plane every 2-3 days. As the water was going down, I had to move the plane out deeper to keep it from being stuck for the rest of the season on the beach. I would keep one line on the tail cleat and one on each wing tie down attached to a large auger type tie down screw. When the water was coming up. the danger is with the tie downs over stressing the wings by pulling down while the floats are pushing up. The other fear is that the plane will pull the screws out of the ground and thus be free to float away. This up and down issue can also be an issue in coastal regions where the tide may change several feet in the coarse of a day. A floating dock or constant attention are really the only options.

The seaplane base at Oshkosh uses bouys achored to the lake bottom. A line is tied to the front of each pontoon and the planes are allowed to rotate into the wind. This assumes a pretty protected area, a secure bouy and that your floats don't leak too much.

The best sollution is to get the plane out of the water, but that is not always possible or convenient.