S. P. of Archer asks, “I was canoeing down the Santa Fe River last weekend and I came upon a dock that extended a good 30 feet or so out into the river. It has a big waterslide and a double-decker platform. It was huge. Can the owner do that? It seemed to me that it was way too big and could cause a problem for boaters, like me, if a motor boat came speeding along as I was going by. Is that legal?