jonnythan:
A drysuit is a drysuit, really. It keeps you dry. The important part is fit. You want it to fit snugly but not interfere with your range of motion. Baggier is worse.. and IMO trilam is the way to go. Neoprene is heavy and just sucks in general.
I used to be a die hard trilam fan. A trilam bigot even...until I had a zipper leak and was forced to borrow a neoprene drysuit. I was very impressed. Now I own a neoprene drysuit and the trilam is strictly a backup.
You get a much snugger and more streamlined fit with a neoprene suit and still do not sacrifice anything in terms of range of motion. Even with a custom trilam, there are still tradeoffs between range of motion and bagginess and the degree that you have to tolerate one or the other varies with the underwear. I have found I am much more comfortable in unusual attitudes with a neoprene drysuit as with the snug fit, there is not nearly the tendency for air to rush to your feet. You can also comfortably dive with much less air in the suit and are less prone to a squeeze in a neoprene suit. I have found that when diving doubles and stages where use of the wing for bouyancy control is manadatory, that much less attention needs to be paid to maintaining the volume of air in suit and that task loading is reduced with no sacrifice in comfort.
In my opinion, a neoprene dry suit is also slighty easier to get into as there is normally no requirement to don heavy underwear first and then don the shell. It feels less bulky and is more comfortable to wear in most circumstances
Best of all, with a good fitting neoprene suit, your streamlining is as good as with a wet suit which benefits efficiency in speed and air consumption. Unlike nearly all shell suits, it virtually disapears once you are in the water.
As for longevity, I have heard that neoprene suits do not last as long, but my spouse has put about 4 years and 300 dives on her Atlan neoprene drysuit and it is still going strong - and she bought it used with an unknown number fo dives already on it. That is about as many dives as I have put on either of my trilaminate suits, so if a neoprene suit lasts until you want to replace it anyway and costs half as much initally, it's hard to argue with the economics of a neoprene suit.
Weight wise, with a 7mm neoprene drysuit I need about 4 more pounds than with a trilam in most circumstances but I also stay warmer. For travel the suit is slightly heavier but not bulkier to pack than a trilam and it neccesarily heavier underwear.
So my thoughts are to not rule out a neoprene drysuit based on old predjudices and beliefs associated with older neoprene suits that had problems with valve placement and zipper designs that are no longer a factor. A well designed neoprene drysuit can be an excellent choice.
If you go with a shell suit, you definitely want to go with something with a lot of stretch to it rather than with a traditional trilam material.
