Exposure suits allow your body to maintain some warmth underwater by slowing down heat loss. Body temperature decreases quickly when submerged in water, and we place ourselves at the risk of losing too much body heat when we dive without the right gear. This is why wearing an exposure suit—either a
wetsuit or
drysuit—is a must.
Your will cool quickly in response to diving in waters that are cooler than your body’s temperature, and even in the warmest tropical waters you will likely still need a bit of thermal insulation to keep yourself warm and comfortable during long dives. Exposure suits also give your skin protection from the harsh sun, which divers tend not to notice when they’re underwater, despite the fact that it still affects their skin.
One common question asked by both divers and non-divers alike is: What’s the difference between a wetsuit and drysuit, and how can you tell one from the other? The most obvious answer comes from the name itself—a drysuit keeps you dry and a wetsuit does not.
In this article, we take a closer look at the main differences between the two in order to help you decide which suit is best for your needs.
Wetsuit vs. Drysuit
A wetsuit provides thermal protection for divers and works on the principle that your body is the best source of heat. To help contain this heat underwater, these suits are made with a closed-cell foam material, which is filled with thousands of tiny gas bubbles trapped within the structure. Once you enter the water, the material allows a thin layer of water through the suit, filling the space between your body and the inner layer of material. This layer of water warms up thanks to your body temperature and helps keep you comfortably insulated throughout your dive.
Scuba wetsuits are designed to fit close to the body. A loose fitting wetsuit will let water flow in and out of the gaps between the wetsuit and your skin, which means your body will end up wasting energy to heat the “new” water, making it pointless for thermal insulation.
A wetsuit also has to be thick enough to suit the temperature of the water you’re diving in. Wetsuits vary in thickness—the thicker ones provide more protection and insulation for colder waters, while the thinner ones offer lighter insulation in warmer waters. However, it’s important to remember that everyone’s body is different, which is why a specific suit’s thermal performance will normally vary from person to person. Some scuba divers can dive in tropical waters wearing only a lycra body suit, commonly known as a dive skin, while others will need a 2mm-thick (or more) wetsuit. Some scuba divers can dive in cold water wearing only a 6mm-thick wetsuit, while others need the protection of a drysuit.
What is a Dry suit?
A
drysuit, as the name indicates, keeps you completely dry by ensuring that no water gets into the suit. It can be made out of foam neoprene, crushed neoprene, vulcanized rubber, or heavy-duty nylon. It’s also fully sealed and uses a combination of wrist seals, a neck seal, and a
waterproof zipper to keep you dry.
Drysuits fit more loosely than wetsuits and allow you to wear clothes or other insulating layers underneath. They work by keeping an insulating layer of air between the body and the suit, which you can control with inflator valves that allow you to add gas as you go deeper. Drysuits also make use of exhaust valves to release air during ascent.
The inflator valve is similar in function to the power inflator on a buoyancy compensator vest and is often situated in the middle of the chest on the suit.
Maintaining neutral buoyancy in a drysuit requires certain skills. Drysuit diving takes some getting used to and usually requires training and experience. If you’re interested in trying it out, we highly recommend receiving proper training from a qualified instructor.
Comparing Wetsuits and Drysuits
If you’re trying to decide whether to purchase a wetsuit or drysuit, here are a few key differences that you should consider:
Thermal Insulation
Wetsuits use a layer of water (that is warmed by the wearer’s body) to help keep the body insulated, while drysuits use a layer of air and are fully sealed to prevent water from entering and coming into contact with the skin. The latter has the advantage here, as water conducts heat over 20 times faster than air.
Divers can wear undergarments with both suits to further increase thermal insulation, but drysuits, thanks to their loose fit, enable you to wear thicker garments underneath.
Mobility
Due to their skin-tight fit, wetsuits typically make it easier to move quickly and comfortably underwater. Drysuits, depending on the material used, are much baggier and can result in some drag as you move underwater. This means you may end up being much slower than if you had been wearing a wetsuit.
Lifespan
Drysuits are traditionally more expensive than wetsuits due to their complex construction, which enable them to work in numerous environments. Then again, even the most expensive drysuits can actually be more cost-efficient than high-quality wetsuits as the former can last over 15 years with proper care and maintenance.
Value
With the emergence of more brands and the availability of newer materials, quality entry-level drysuits now cost as much as higher-end wetsuits. However, drysuits being available at much lower prices certainly doesn’t make them lose their long-term value, as they can often retain their value for resale—unlike wetsuits, which are more likely to deteriorate after a few years of regular use.
Exposure Suit Recommendations
| Temperature* | Recommended Suit Thickness* |
| 76°F to 86°F | 1.6mm Neoprene or Lycra Dive Skin/Wetsuit |
| 69°F to 84°F | 3mm Neoprene Wetsuit |
| 64°to 77°F | 5mm Neoprene Wetsuit |
| 49°F to 75°F | 6.5mm Neoprene Wetsuit |
| 33°F to 66°F | 9.5mm Neoprene Drysuit |
*Temperature and suit thickness based on average manufacturer recommendations
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