We have a couple members of our EAA chapter who used to do this quite often. They have the Alaskan bush wheels/tires on their Cubs and land on gravel bars in the rivers around here--well, gravel bars is an understatement, we are talking rocks about the size of a volleyball. Anyway, they used to have a ball skimming the water surface, throwing up big rooster tails with their wheels.
About a year and a half ago, the retired crop duster got a little too slow while skimming & flipped his plane. Fortunately, he was almost to a gravel bar when it happened, which is where part of the plane came down, with the cockpit in shallow water. He and his passenger were trapped inside & couldn't get the door open until the other pilot landed on the gravel bar and helped out. If they had landed in deep water, they would have been in deep doo-doo as only the gravel bar kept them from sinking.
Haven't heard them talking about skimming the water since then. The ex-crop duster has his Supercub flying again.