Thanks for the response, it sounds like a good idea, but (while still important) ease of mobility isn’t the main point I’m looking for, just more down time in fairly shallow water. With a single tank, I get about an hour(+ or -), and was hoping for 2-3 hrs each dive. As far as mobility/heavy lifting is concerned, I suppose I could do a dual tank setup, but highly doubt I’d enjoy the added bulk of a 2nd tank. And, I don’t want to be limited to a dock or 30-40 ft from a boat. I was thinking maybe 2 tanks up top on an inner tube type setup, but seems like there would be more potential for stuff to go wrong. Which is mainly why I wanted to just try out a hookah first.