Did you know that one of the main reasons for calling a dive early is because the diver is cold?
Getting your gear right can make or break a dive trip - no one wants to be 20 minutes into a dive shivering in their wetsuit or baking in their dry suit. Warmth can be affected by season, depth, length of dive, and every diver is unique. If you are new to dry suit diving or are changing your kit set-up, finding a thermal layering system that works for you can be confusing.
We’ve put together some helpful guidelines and top tips from Fourth Element to get you started…
CHOOSE A BASELAYER
A good base layer worn next to the skin is critical - it must manage moisture and keep your skin as dry as possible. Whether you like it or not, there will be some moisture inside your suit; hopefully, it’s just from perspiration, but at some stage, it is likely that it will also be water from a leaky seal, a zipper, or a more catastrophic leak. Keeping this moisture away from your skin is the job of a good base layer.
J2 BASELAYERS: This is a super-light wicking layer for layering under any undergarment to manage perspiration and small suit leaks without affecting buoyancy. It wicks moisture away very quickly. Its anti-bacterial properties also make it the perfect base layer for drysuit diving trips in which multiple days of diving are planned.
XEROTHERM: The Xerotherm provides good wicking performance, coupled with great thermal protection. It can be worn next to the skin as a baselayer or over the J2 as a thermal layer. It works so well when wet that some divers do not notice leaks in a suit until after the dive.
The Fourth Element J2 Baselayers were developed for the US Deep Cave Diving Team’s 2013 expedition to explore the J2 cave system in Mexico, enabling long, repetitive wear without the risk of skin infections developing.
TOP TIP: Cotton t-shirts soak up sweat and keep your skin wet and cold, so always use a specialised base layer.
CHOOSE A THERMAL UNDERSUIT
Thermal layers are there to slow heat loss from the body, keep you comfortable, and help with gas management and buoyancy within the suit. The key is to find thermal layers that perform without being restrictive, bulky, or too buoyant. It’s easy to think that the thickest under suit is the warmest, BUT fabric technology, wicking properties, and attention to the key areas that are most exposed mean that today’s under suits can give full thermal performance without being bulky and restrictive.
ARCTIC: Using a combination of fast-wicking, high-insulation fabrics, the Arctic creates a micro-climate around the diver, keeping the body dry and warm. A high-density inner fleece provides superior insulation, with maximum comfort and wicking, whilst the
HALO A°R: Incorporating highly advanced thermal technology and one of the most insulating materials ever developed, the HALO A°R one-piece achieves extreme thermal protection from a thinner, less buoyant diving under suit.
X-CORE: For really cold or longer exposure conditions, the X-Core vest can be worn either next to the skin or over the base layer and provides significantly greater thermal protection, with minimal impact on buoyancy.
I’M DIVING IN TROPICAL WATERS - 26 - 30°C
Examples include Singapore, Malaysia, Thailand, Indonesia, Philippines, Florida, Cozumel, and the Red Sea.
GOING DIVING?
Choose a diving wetsuit! Wearing an all-purpose wetsuit for diving won’t keep you warm because standard neoprene compresses quickly at depth and loses its thermal properties.
I AM HOT BLOODED.
Add a Thermocline vest or a 3mm neoprene hood for your 2nd or Proteus II wetsuit, or 3mm Xenos wetsuit. If you prefer to go neoprene-free, use the Thermocline top and leggings.
I FEEL THE COLD.
Thermocline Top and/or leggings to keep the core warm, then a 3mm Proteus II / Xenos wetsuit over the top. Don’t forget a 3mm neoprene hood!
ARE YOU A DRYSUIT DIVER?
You won’t need much thermal protection, but wear Xerotherm top and leggings under your drysuit - they will wick away moisture and keep you warm if you’re diving deeper.
I’M DIVING IN TEMPERATE WATERS - 18 - 25°C
(Or for longer durations)
Cave diving in Indonesia or Mexico, or shallow diving in summer in temperate countries like Europe, Canada, New Zealand.
I AM HOT BLOODED.
5mm Proteus II or 7mm Xenos wetsuit, with 5mm hood.
Add a Thermocline vest and leggings for longer dives.
Adding layers means adding more lead to combat the buoyancy - BUT our thermocline layers are neutrally buoyant, so you don’t need to change your weights set-up!
I FEEL THE COLD.
It’s drysuit time! Start with J2 as your next-to-the-skin base layer (to wick away any moisture), and wear Arctic top and bottoms on top to keep you toasty.
TOP TIP
Diving deeper? Add an X-Core vest for extra warmth. Wear it between your J2 Baselayer and your Arctic to maintain body heat for longer.
I’M DIVING IN COLDER WATERS - 12 - 18°C
(Or longer duration cave/deco dives)
Cooler months in Europe and USA, cave diving in Australia or the Mediterranean. Unless you’re ultra hardcore, it’s definitely time for the drysuit to come out!
I AM HOT BLOODED.
Grab your J2 baselayer and wear the Halo AR one-piece over the top. A 5mm hood will keep your head warm, and 5mm neoprene gloves will keep fingers from getting too cold.
I FEEL THE COLD.
Put a Xerotherm top or X-Core vest over the top of your J2 Baselayer before donning your Halo AR layer. This will give a boost to your core. Grab a 5mm hood, and if your hands are cold, switch to dry gloves with Xerotherm or Halo AR gloves underneath.
DIVING DEEPER?
Add an X-Core vest for extra warmth. Wear it between your J2 Baselayer and your Arctic to maintain body heat for longer.
LAYER UP
By the 3rd or 4th dive of the day, you will be tired, so you’ll feel the cold more – add a hood or an extra thermal layer to stay toasty.
I'M DIVING IN COLD WATERS - 4 - 11°C
Examples include Scandinavia, Baltic, Northwest USA and Alaska
I AM HOT BLOODED.
J2 Baselayer, with an X-Core vest over the top to keep your core toasty. Then don your Halo AR one-piece and don’t forget your thermal gloves under your drygloves! Switch up to a 7mm hood.
I FEEL THE COLD.
This is where layers really are your friend! Start with the ever-faithful J2 to wick sweat away from your skin and keep you dry. Next, add Xerotherm top and/or leggings as your first thermal layer. Add an X-Core vest if you are doing a longer or slightly deeper dive, and then don your Halo AR before putting on your drysuit.
DIVING DEEPER?
Add an X-Core vest for extra warmth. Wear it between your J2 Baselayer and your Arctic to maintain body heat for longer.
If you don’t have a Halo AR yet, you could layer up with a J2 Baselayer, Xerotherm, and Arctic, with an X-Core vest below the Xerotherm for good measure. You may be a little more bulky though, so remember to check your buoyancy!
DON’T FORGET THE EXTREMITIES!
Whilst it’s vital to protect your core through a dive, keeping your head, fingers, and toes warm is just as important.
HOODS.
A hood helps maintain a good body temperature, even on cold-water dives. Choosing a 3mm, 5mm, or 7mm hood to use with your wetsuit or drysuit will make the world of difference to your dive. Wearing a cold-water hood with a neoprene skirt means you can tuck it into your drysuit warm-neck and add an additional layer of warmth where your blood flow is more concentrated.
GLOVES.
Cold fingers are not only miserable but also affect your dexterity, making it challenging to adjust your kit in and out of the water. If you’ve ever tried to inflate your SMB underwater with numb hands, you’ll know what a struggle it can be. So unless you are only diving in the tropics, gloves are a must-have.
If you are diving in a wetsuit, choose 3mm or 5mm neoprene gloves. If you are diving in a drysuit, you can still opt for neoprene gloves, but for colder dives, we recommend switching to a dry glove system with thermal gloves underneath. Your fingers will thank you!
SOCKS.
Cold feet on a dive can ruin concentration, and an otherwise fantastic dive can be marred by discomfort and unease. As a general guide, choose socks that match your thermal layers (Xerotherm socks with Xerotherm layers, Arctic Socks with Arctic layers, etc.), but if you know your feet get extra cold, upgrade!
TOP TIP
If you are using full-foot fins, neoprene socks can not only help keep feet warm but also prevent the fins from rubbing.
Whether you're gearing up for warm tropical waters or braving the depths of colder seas, choosing the right thermal protection is essential for a comfortable and safe diving experience. At Mike's Dive Store, we understand the importance of quality gear, which is why we recommend Fourth Element's range of thermal layers and undersuits. Their innovative designs, like the J2 Baselayers and Arctic undersuits, ensure you stay warm and dry without sacrificing mobility or buoyancy control.
Explore the full collection of Fourth Element at Mike's Dive Store, where you can find everything you need to enhance your diving adventures. Visit our London Dive Store or browse online at www.mikesdivestore.com to discover why divers worldwide trust Fourth Element for their underwater journeys.
Happy diving!
