Mastering Exposure Protection: Your Guide to Scuba Diving Suits and Thermal Comfort

Anyone who knows me well knows that I get cold easily. I generally wear a warmer exposure suit than other divers in the same water temperature. Early on in my diving career, I didn't have the right thermal protection for most dives, mostly due to suit thickness and fit. I would find myself halfway through a dive freezing cold and wishing the dive would be over soon. It was only after I discovered good thermal protection that I really started to enjoy longer dives in all water temperatures, from diving icebergs in the Arctic to warm tropical waters.

This personal journey highlights the critical importance of exposure protection in scuba diving. Whether you're like me and prone to feeling the chill or if you're simply seeking comfort and enjoyment during your underwater adventures, choosing the right exposure suit can make all the difference in your diving experience. Let's take a deeper look at exposure protection and the various options available, including traditional scuba diving wetsuits, specialized free diving wetsuits made of open cell neoprene, drysuits and electric heated vests, to keep you warm, comfortable, and ready to explore the depths.

Wetsuits

Wetsuits are the most common type of exposure protection worn by scuba divers. Made from neoprene, a synthetic rubber, wetsuits work by trapping a thin layer of water between your body and the suit, which your body then warms up. This layer of water acts as insulation, keeping you warm even in cooler waters. Wetsuits come in various thicknesses, typically measured in millimeters, ranging from 1mm to 10mm. A properly fitting wetsuit is crucial for its effectiveness. A suit that is too loose in any part of the body can allow water to flow too easily, compromising its insulating properties and making the diver cold. Ensuring a snug fit without restricting movement is essential for maximizing thermal protection.

For cold water diving, some divers wear a two-piece style 7mm wetsuit that is sometimes referred to as a “farmer John”. This style of wetsuit adds a double layer of neoprene over the torso. Some wetsuit manufacturers put thicker neoprene in the torso and slightly less neoprene in the arms and legs to provide more flexibility. These are usually labeled as n/m where n is the thickness in the torso and m is the arm/leg thickness. So for example, a 5/4 wetsuit would have 5mm in the torso and 4mm in the legs and arms.

Pros:

• Versatility: Wetsuits are suitable for a wide range of water temperatures, making them a popular choice for most diving conditions.

• Mobility: Wetsuits are flexible, allowing for ease of movement underwater.

• Affordability: Compared to drysuits, wetsuits are generally more affordable, making them accessible to a wider range of divers.

• UV Protection: Wetsuits provide great protection for the skin during long days in the water in glaring tropical sun

  Cons:

• Limited Thermal Protection: In colder waters, wetsuits may not provide adequate insulation, leading to discomfort or even hypothermia.

• Water Exchange: Wetsuits can still let water flow in, which can cause a diver to feel cold, especially during extended dives or in rough conditions. Some manufacturers add a neck dam to minimize the water flowing through the suit.

• Durability: It's important to note that wetsuits experience compression with each dive, which can reduce their thermal protection properties over time. Typically, a wetsuit needs to be replaced every 200-300 dives to maintain optimal insulation and performance.

Semi-dry Wetsuits:

Semi-dry suits bridge the gap between wetsuits and drysuits. They are constructed with thicker neoprene and feature better sealing mechanisms at the wrists, ankles, and neck to minimize water ingress. Unlike wetsuits, semi-dry suits aim to keep a diver relatively dry throughout the dive by reducing water exchange.

Pros:

• Improved Thermal Protection: Semi-dry suits offer better insulation than wetsuits, making them suitable for colder waters.

• Reduced Water Exchange: The tighter seals of semi-dry suits minimize water ingress, keeping the diver drier and warmer during the dive.

• Comfort: Semi-dry suits provide a balance between warmth and flexibility, offering greater comfort during dives.

Cons:

• Cost: Semi-dry suits are typically more expensive than wetsuits, although they are usually more affordable than drysuits.

• Buoyancy Control: Semi-dry suits may require additional weight for buoyancy control due to their thicker neoprene material.

• Difficult to Don: Generally, semi-dry’s are harder to get into than a regular wetsuit.

Free Diving Wetsuits (Made of Open Cell Neoprene):

Free diving wetsuits made of open cell neoprene are gaining popularity among scuba divers seeking enhanced warmth and comfort underwater. These wetsuits are designed with the specific needs of free divers in mind but can also be used for scuba diving. Unlike traditional scuba diving wetsuits, free diving wetsuits are constructed from open cell neoprene, a type of neoprene with a porous surface that provides better insulation and minimizes water flow.

Pros:

• Superior Insulation: Open cell neoprene wetsuits offer excellent thermal protection, keeping the diver significantly warmer than equivalent traditional scuba diving wetsuits of the same thickness.

• Minimal Water Flow: With no stitched seams, which are common in traditional wetsuits and often the source of water flow, free diving wetsuits minimize water ingress, keeping the diver drier and warmer during the dive.

• Enhanced Comfort: The snug fit of open cell neoprene wetsuits provides superior comfort and flexibility underwater, allowing for ease of movement during dives.

Cons:

• Difficult to Don: Free diving wetsuits made of open cell neoprene are harder to put on compared to traditional scuba diving wetsuits. Divers often need to cover themselves in conditioner or use other lubricants to ease the process of getting into the suit.

• Increased Risk of Damage: Open cell neoprene wetsuits are more prone to tearing compared to traditional neoprene wetsuits due to their softer and more delicate nature. Careful handling is required to prevent damage during donning and diving activities.

• Limited Durability: Due to the delicate nature of open cell neoprene, these wetsuits may have a shorter lifespan compared to traditional scuba diving wetsuits, especially if not properly maintained and cared for.

Drysuits:

Drysuits are the go-to choice for diving in cold water or for prolonged exposure to water. Unlike wetsuits and semi-dry suits, drysuits are designed to keep the diver completely dry by sealing out water entirely. The key to staying warm in a drysuit is choosing the correct thermal protection to wear under the drysuit. Wearing a wicking base layer is usually sufficient in tropical waters. As the water temperature gets cooler, choose the correct thermal undersuit to layer on top of the base layer.

Pros:

• Complete Dryness: Drysuits prevent water from entering, keeping the diver completely dry throughout the dive.

• Extreme Thermal Protection: Drysuits excel in providing insulation in cold water conditions, allowing divers to stay warm even in icy temperatures.

• Buoyancy Control: Drysuits offer redundant buoyancy control should a BCD bladder fail during a dive.

Cons:

• Mobility: Drysuits are less flexible than wetsuits and semi-dry suits, which can impact mobility underwater.

• Learning Curve: Proper training is essential for using drysuits, as they require specific skills for donning, doffing, and managing air in the suit.

• Cost: Drysuits are the most expensive option among exposure protection suits, which may be a barrier for some divers.

• Peeing: Unlike a wetsuit, wearing a drysuit complicates the need to relieve oneself. You have the choice of either holding it, using adult diapers or getting a pee-valve installed in the suit (which adds further cost).

Electric Heated Vests:

Electric heated vests offer a modern solution to combating cold temperatures during dives. These vests feature battery packs comfortably situated on the sides, just below the armpits, providing convenient power for warmth. Controlled with a wrist-worn remote resembling a watch, vests like my Venture Heat model offer high, medium, and low heat settings. With a battery life of approximately three hours, these vests maintain warmth throughout the dive, particularly when judiciously adjusting the power setting. While they come with a hefty price tag ranging from $650 to $800, they prove invaluable for extending dive times in chilly conditions. Additionally, they serve as versatile accessories, fitting snugly under a wetsuit for added warmth during surface intervals or chilly moments above water, ensuring comfort and enjoyment throughout the dive experience.

Heated vests (and other undergarments) are also available as an accessory to drysuit systems. These vests are designed to stay dry and are connected to a battery that is attached to the BCD. The connection is made through the inflator valve on the drysuit.

Don’t Neglect Your Extremities:

Keeping your core warm is important but don’t forget to protect fingers, toes and your head.

Hood Selection:

Hoods are critical for retaining heat around your head. Choose the thickness that suits your conditions:

• 3mm: Ideal for mild cold

• 5mm: Suitable for moderate cold

• 7mm - 11mm: Best for extreme cold

Gloves: A Must-Have for Dexterity and Warmth

Cold fingers affect comfort and dexterity. Consider:

• Wetsuit Diving: Opt for 3mm or 5mm neoprene gloves

• Drysuit Diving: Explore a dryglove system with thermal gloves

Socks: Keeping Your Feet Toasty

When drysuit diving, proper socks are crucial for preventing cold feet.

• Match with Layers: Align socks with your thermal layers.

• Upgrade for Comfort: Invest in high-quality socks for maximum warmth

Conclusion

In addition to providing thermal insulation, exposure protection suits offer an added advantage when diving in waters inhabited by stinging critters such as jellyfish and hydroids. Choosing the right exposure protection suit is crucial for a safe and enjoyable diving experience. Consider factors such as water temperature, comfort, mobility, and budget when selecting between wetsuits, semi-dry suits, and drysuits. Remember to invest in proper training and maintenance to ensure your suit performs optimally on every dive. Whether you're exploring tropical reefs or braving the icy depths, the right suit will keep you warm, comfortable, and ready for adventure.