EzeeDiver
Registered
Hey Tim, I am going ot throw this one out there to you as well. You can do sidemounted independent doubles. That way when you need that much air you can carry two tanks(or more) or if you are doing shallower shorter dives you will need only one.
I know you are taking Fundies with Bob Sherwood, and the sidemount setup does not fly with GUE, but I am throwing it out there as an option.
I am starting to want to do some of the Northeast wrecks and they are deeper than I would feel comfortable having a single tank. I am working now with a single LP112 and a sidemounted AL40. You will probably see me at Dutch sometime soon getting some time in and getting used to the new setup.
Brent
+1
I went the tec route in January and decided to do it in sidemount (instructor also a sidemount instructor). When I made the decision to go tec, I first took a sidemount specialty class to get used to the gear configuration before Tec 1. Very easy transition from 1 to 2 tanks, at least for me. I used 2 AL80s and 2 LP95s. The AL tanks are great for wetsuit dives, but I use the LP95s with my drysuit (don't need weightbelt). If your aim is redundant air supplies, consider 2xLP45 steel tanks. Very small, light(er) and easy to carry, and don't have enough gas to tempt you to go beyond recreational limits. Also, in sidemount you have direct control over your gas supplies as they are right by your hands. Also, the sidemount specialty course is a recreational course, and does not mean you are a tec diver or qualified to make extended range dives. So...you could go sidemount, have your redundant gas supplies and get comfortable before deciding to go tec. It has worked well for me.
Something else to think about...most resort dive operators in tropical locales don't like the idea of someone carrying 2 tanks on their dives which last 35 mins. If you want to use 2 tanks on a vacation, make sure to call ahead and ask the operator's policies. I use sidemount all the time now at my local quarry, and can even travel with the setup, all I need to bring is my extra reg and cam bands, and I can sidemount AL80s or whatever tanks the operator has on my trip.
Keep diving, get experience in multiple environments and practice. Good luck and happy diving!