For me, the main thing is being close to shore (as I normally dive off shore) I dive year around, depending on when the ice forms (I won't dive under ice unless it is with a divemaster, being an "overhead environment"). The main thing I consider is what the consequences are should a valve fail, which would flood the suit and hasten hypothermia which, believe me, is very debilitating. As has been recommended in previous posts, remove and replace your mask to get used to the shock of truly cold water, most people gasp with a face full of it, which would be bad news at depth for us divers (I recently switched to a FFM and it took a great deal of practice in cold temps to remove it and put the back up mask on underwater~ I'm still not completely confident that I could perform the switch at depth in cold water, it really does make a big difference).
The other considertion is what type of drysuit you're wearing, neoprene or vulcanized? neoprene is warmer and retains some heat (so I'm told) if a valve fails where vulcanized becomes negative and much colder. The difference of course is according to how much weight you're willing to wear during the dive. As far as the "dry gloves" are concerned I wore five finger gloves for quite awhile (warming them with hot water out of a thermos) with good, comfortable results on winter dives, but the three finger mits, although difficult to get on alone (tight wrists are a must!) are fantastic for me. The coldest part of my winter dives are when I exit and undress. I think winter diving is the best for the visibility and lack of activity, the only thing is the funny looks you get when you ask people to "zip you up" when you're wearing enough underclothes to make zipping up alone (back zipper) impossible. Good luck, and take care~ Jim
