It doesn't calculate O2 exposure ( no bid geal to me ). It won't do "cave profiles" (multilevel dives where the next level is above the first required stop). V-planner and decoweeneie will both do this. Again, not a big deal but it's nice to have the option for caves that do that to you. There are, of course other ways. When calculating a range (table) you can have only one variable depth or time. Voyager does both. Again, just a convenience. Oh, no closed circuit. I don't have a rebreather but I dive with some that do. I went this rout for a portable because it was much less expensive than a lap-top, and the batteries last longer. In, fact I got an extra palm pilot so I would have a backup on trips. My palms too are dedicated to running Dplan. I don't have any other use for such a thing. I was going to get decoweenie also but I think I'll save the $75 and use what I have. Dplan is extremly easy to use. You can learn it in a bout three minutes and it does all of the important stuff.
