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A warm diver is a happy diver

As we learned last month, the amount of thermal protection a diver needs depends on the temperature of the water and, to a lesser degree, the diver’s susceptibility to feeling cold. Options for thermal protection run the gamut – from a  lycra “skin suit” all the way up to a toasty warm drysuit.  This month, we’ll explore the lower end of this spectrum as well as point out how this gear can keep us safe and make our diving easier.

Dive "skins" and rashguards
Even when the water is plenty warm, many divers still want protection from the sun and accidental abrasions. In many cases a rash guard or thin lycra suit will suffice. Lycra dive skins range from a single layer of lycra up to 0.5 mm fleece lined skins. Most of these suits have little to no inherent buoyancy and do not require a weight adjustment. They may preserve a little bit of body heat, but are mainly for sun and abrasion protection. They can also be worn under a wetsuit, adding only a little warmth, but making it MUCH easier to don the wetsuit.

 

Wetsuits

To stay warm, the next step up in protection is a wetsuit. Most modern wetsuits are made of neoprene. Early suits were made of rubber which proved to be bulky, heavy, restrictive, and not very warm. Neoprene, on the other hand,  is made by taking that rubber and infusing it with tiny air bubbles during the manufacturing process. The air bubbles, along with the rubber, provide excellent insulation. One drawback of neoprene: it wears out in direct relation to exposure to water pressure because the infused air bubbles compress and expand during a dive. Eventually, the air is forced out and the suit doesn’t have the same insulating characteristics. A second problem is that as you dive deeper, the infused air bubbles are compressed and provide less insulation. Ironically, that means that at depth- where the water is typically colder- your wetsuit provides less thermal protection. So plan accordingly in your suit selection.

GET (the) FIT!

A wetsuit is exactly what its name implies – a suit that is wet on the inside. The suit allows a layer of water between the diver’s skin and the suit. Our body heat warms this water which helps provide insulation. The rest of the insulation comes from the suit itself. That water layer is key to keeping a diver warm. If a suit is too loose, that layer of water is constantly being replaced with new (cold!) water which the body must then heat up. You can see how a leaky wetsuit is not a good way to stay warm.

So the number one requirement for a wetsuit is the proper fit. Otherwise, regardless of the thickness, it won’t keep you warm! A suit that is too large allows for too much water flow. A suit that is too small will pull around the seals and also allow water to enter (in addition to being uncomfortable and even hazardous.)

Length and thickness

Wetsuits run quite a range in length, thickness, and features. Depending on where and how much they dive, many divers accumulate a virtual wardrobe of wetsuits so they can be comfy in any conditions.

 

As the water gets a little cooler (and even for longer dives in tropical waters) the next step up in warmth from a dive skin is often a shorty wetsuit. Typically 2 or 3 mm, these suits mainly cover the body’s core, and have short sleeves and legs.

 

 

For colder dives, you may want a full suit which covers all the way to the wrists and ankles. Depending on the water temperature you plan to dive in, you can select a full wetsuit ranging in thickness from 3 mm up to 7 mm or more. You can also choose a one-piece full suit style or a two-piece “farmer john” style with a jacket and bib pants.

 

 

"Bells & Whistles"

Liners
As wetsuit technology has developed, many features have become available to make a wetsuit more comfortable and effective. With original neoprene suits, the inside of the suit was basic rubber making it very difficult to put on. Divers wet them first and even resorted to coating their bodies with hair conditioner to make the suit easier to slip on. Most suits nowadays are lined on the inside with lycra or something similar making it much easier to slide into the suit.

Openings - good, better, best
Seams and zippers are also a possible point of water entry into the suit that can make a wetsuit less effective. At the low end, seams are merely sewn together. In the middle, glue is added to the seams. And on the high end, seams are sewn, glued, and taped. Each step eliminates some portion of water flow. Zippers at the low end have no backing and rather loose fitting teeth. In the middle, the teeth fit closer and tighter. At the high end, not only are the teeth close and tight, but a flap of neoprene covers the inside of the zipper preventing water entry.

The next point of possible water entry is where the body protrudes from the suit – the neck, wrists, and ankles. Here again, there are a range of options. At the low end, the wetsuit material just stops with a stitch or roll to keep it from fraying. But the material is free to slide and move as the diver moves, allowing water to pass in and out. Higher end suits provide a more watertight seal. Some suits don’t cover the last few inches of the sleeve with lycra and rely on the rubber to provide a seal. Better suits use a material that sticks to the skin better while being flexible enough not to gap as the diver moves.

Design and Material “upgrades”
You can imagine how wearing a neoprene suit can make it hard to move around. So another nice recent development is the use of different thicknesses of neoprene in different parts of the body - thicker over the core and thinner over the extremities. For instance, a “5/3” suit has a 5 mm thickness over the body and 3 mm thickness in the arms and legs allowing for easier movement. Some suits even take it a step further and even use different types of materials as well as different thicknesses. These new materials are designed to be more stretchable and therefore making the suit easier to don and doff and more comfortable to move around in. An example is the Mares Trilastic wetsuit.

And speaking of new materials, the inside lining on higher quality suits has advanced from plain lycra to advanced heat-reflecting and anti-microbial materials to keep you warmer and your suit from getting stinky.

 

 

IT'S A TRADEOFF...


Of course, many of these advanced features do have drawbacks. Every feature adds cost, so you have to consider your budget. Second, they are generally not as strong or long lasting as basic neoprene, so your suit may not last as long as a basic neoprene suit. On the other hand, these more advanced suits will fit better, keep more water out, keep you warmer, and be more comfortable, making your dives much more pleasant.

 

Dive smart. Dive warm

Being cold during a dive is no fun and can be dangerous, so get the best suit you can afford. Get the right thickness for your conditions and make sure it fits.

Tune in next month when we’ll talk about “wetccessories.”