Fred,
Just as the catamaran operators walk up and down the beach, so will the jet ski sales people. The catamarans dont "troll" up and down the beach and they do great business. The jet ski operators business model will change, and that will become the new norm. It will also create more jobs as anyone wanting to jet ski will be shuttled up to the launching area farther up the beach, far from the swimmers by the resorts.
Read my previous post on who will be doing the enforcement.