Majority of divers scuba dive in warmer waters where skin suits, half wetsuits, full wetsuits or even no wetsuits are needed to prevent your body from loosing heat to the surrounding water. It is proven that, in order for our body to keep up with the heat loss, the water needs to be at least 34 degrees Celsius (~92F). So, even if you are diving in the tropics without a wetsuit, you will eventually get cold towards the end of your dive (depending how long your dive is of course). You can read about wetsuits in my earlier post .
However, what if you are going to dive in a bit colder water? Regular wetsuit’s neoprene, even thick one with a hood and booties will not be of much help after a few minutes because it will not insulate your body enough. During your dive you will quickly start loosing heat and risk the feared and dangerous hypothermia. Do not worry though, if you live in a colder climate you still can dive. The introduction of modern dry suits allows us to enjoy dives even in sub zero Celsius (32F) waters. Dry
suits are filled with air rather than water, like in wetsuit and since air slows down the heat loss 25x more than water, your body stays warmer. As the name indicates, you stay dry during your dive which is a very bizzare feeling to get accustumed to if you are used to diving in a wetsuit. Also, to add more insulation into the dry suit thus adding extra heat loss protection layer to your body, breathable undergarments are put on underneath the dry suit (Thinsulate being a perfect material for this type of undergarment suit).
So, when should you choose a dry suit over a wet suit? Well, this fully depends on many factors, but mainly on your personal experience and your body’s ability to generate heat and aclimatize to a particular water temperature. Other factors include, how cold is the water you will be diving in, how long will your dive be, how much fat tissue you have (the more fat the less heat you will loose), what is your body shape (tall, lean individuals loose more heat) and of course, how active you will be underwater (the more you swim, the more heat you will generate). Finally, you will also need to think about how deep you go, because with regular neoprene wetsuit, the deeper you go, the colder you will be as neoprene looses its insulation capability with depth.
As mentioned above, dry suits are water tight and come in many different shapes and materials. Dry suits cost more than regular wetsuits, however, they last longer if they are properly cared for during pre- and post- dive inspections. To properly pick the right dry suit and equipment for you, it is necessary to keep a few things in mind, for example: do you want to zip it up yourself or have someone else help you, this will determine what type of zipping mechanism you will choose or are you allergic to latex or not, the answer to this question will determine if you use latex seals or neoprene seals around your wrists and neck. What kind of materials are dry suits made out of and how to take care of your dry suits will be discussed in my next posts, so, so please stay tuned and in meanwhile, grab your BCDs, masks and fins and keep diving.