I was reading Bob Marx's book: The Underwater Dig and he mentioned something called an SAS or surface air supply which was way cheaper than a Hookah for shallow water diving. I wonder if they still make these things? This device was produced in 1965 by Outboard Marine corporation. Johnson Motors sold one called the Air buoy and Evinrude sold one called the Aquanaut. Just curious. I have never seen anything posted about these things. Bob wrote that they produced the cleanest air he ever used and he and his divers used them at Port Royal and had over 13,000 hours with no problems. Except having somebody keep the motor running with the small fuel tank. They had a flotation ring and he used it up to 50 feet deep and did not have any problems.