Worldwide, there are a few places where – in the right season – the water is warm enough for you to comfortably make a dive in just a swimsuit. But for the rest of the world, and the rest of the time, a suit adds warmth and makes it possible for you to dive all day in comfort.
The earliest wetsuits were constructed of neoprene that was lined with nylon on one side only, and was difficult to put on and relatively fragile, tearing easily. Divers also found that the needle holes made when sewing the suit would allow cold water to leak in throughout the dive, diminishing the suit’s effectiveness.
Today’s wetsuits are made of high-quality and rugged materials specifically developed for the diving industry, and seams are either taped to prevent leakage, or formed with a welding process that eliminates sewing entirely. A variety of linings provide comfort and warmth, and suits are easy to put on and take off, and constructed to cushion and work well with scuba gear.
In addition to wetsuits, a variety of other suits have come into use over the past half century or so, ranging from UV- and sting-protecting diveskins to drysuits (which not only keep divers warm – they keep them dry as well). They help assure you that, whether you’re diving off the beaches of the Caribbean or under the ice of the Antarctic, you’re going to be warm and comfortable, and you’ll enjoy your dive.
How Suits Work
Wetsuits are designed to provide an insulating layer between you and the water. They keep you warm even when there’s a thin layer of water trapped between your skin and the suit. The thickness of the suit provides an insulating layer, and the fit of the suit reduces the circulation of water. The water trapped inside the suit warms close to your body temperature, and you stay warm as long as there is limited circulation, and enough insulation from the thickness of the suit to prevent you from becoming chilled. The most important features of a given wetsuit are thickness for the type of diving you intend to do, and the fit of the suit so that trapped water does not easily “flush” through the suit as you swim.
Just as modern houses use “dead air spaces” in the walls to retard the loss of heat, dive suits generally use spaces filled with nitrogen gas (in wetsuits or closed-cell neoprene drysuits) or trapped air (in the undergarments used with most shell drysuits) to dramatically slow the rate at which body heat is lost to the surrounding water.
Some manufacturers also use natural or synthetic lining materials that have insulating values of their own. These thin materials can add warmth to a wetsuit without adding bulk, or they can give a Lycra or spandex diveskin the warmth of a thin wetsuit.
In general, when it comes to insulation, the same principle that applies to your house also applies to your suit: the thicker the insulation, the better the suit is at conserving warmth. In wetsuits and closed-cell neoprene drysuits, neoprene thicknesses typically run anywhere from .5 mm to 7 mm. And the insulating undergarments worn with shell-style drysuits can be thin garments that resemble the underwear worn for skiing (used for moderate temperatures) or they can be garments that look almost like stylishly cut snowmobile suits.
Which Kind is Best?
Three things are going to determine how much insulation you’ll want.
One, of course, is water temperature. But it’s just as important to also consider both the length of your dives and the number of dives you’ll be making in a day.
Because no suit completely stops heat loss, you are apt to feel cooler at the end of a dive than you do five minutes after you start. And because heat loss tends to be cumulative, you’ll feel cooler on your second or third (or fourth or fifth) dive of the day than you do on your first dive after breakfast. That’s why, when you go to a tropical destination, the recreational divers on a dive boat might be perfectly comfortable with just a diveskin, while their divemaster (who’s making several dives a day) might be wearing a 3-mil or 5-mil wetsuit, or even a hood.
Insulation needs also tend to be very individual. Water that feels bath-warm to one person might be cool to another. And let’s face it – some of us are just blessed with more “natural insulation!”
You’ll learn in your first open-water dives whether you’re a naturally cool or naturally warm diver. And based on that, and on the water temperatures at your favorite destinations, your local professional dive retailer can help you select the suit that’s just right for you.
Types of Suits
Diveskins are Lycra or spandex suits that have little or no insulation value, but do provide protection against UV rays while snorkeling, and can also protect a diver against light abrasion and mild marine stings. Some people also wear a diveskin under a wetsuit to help make the wetsuit even easier to put on.
Wetsuits are generally made from closed-cell neoprene in which the spaces within the neoprene foam are filled with nitrogen. As the name implies, wetsuits are not water-tight; they allow some water to seep in. But because the insulating neoprene retards heat loss, that water quickly warms to something very close to your body temperature. If you’ve chosen a wetsuit thickness that is right for the conditions, you’ll be warm and comfortable throughout the dive.
Most wetsuit makers offer suits that are anatomically cut (and some offer custom made) to better follow the contours of female divers, male divers, or junior divers. As closeness of fit helps prevent cold spots in a suit, anatomically cut suits can provide great all-day comfort in a wetsuit.
There are a variety of wetsuit styles as well, to fit almost all types of conditions. Some divers prefer to wear a jumpsuit (or one-piece full suit), while others prefer to wear a shorty suit that covers only the diver’s torso. Still others will wear a jacket and others still will wear a jacket with a separate “farmer john” or “farmer jane” covering the diver’s torso and legs.
Wetsuit accessories include neoprene gloves that protect the hands, and boots that make wearing adjustable heeled fins more comfortable. In addition, because almost 75% of all heat loss occurs through the diver’s head, a great investment for most divers is a neoprene hood that can be worn even in warmer water.
Closed-cell neoprene drysuits are made from materials similar to those used in wetsuits, but they are watertight. These suits may or may not be used with undergarments to add additional insulation. As hydrostatic pressure (the pressure of the surrounding water) will tend to compress the volume of air within any drysuit as the diver goes deeper, these suits – like all drysuits – are equipped with inlet valves that allow the diver to add air as he or she descends, and exhaust valves to vent air off on the way back to the surface. The inlet valves are similar to the low pressure inflator valves used to inflate BCs and are connected through the diver’s regulator to the tank.
Shell-type drysuits may be made of thin trilaminates, latex-coated canvas, crushed neoprene, or a combination of materials. These suits, in and of themselves, add little insulation value, but they are made to be worn with insulating undergarments that add the actual protection against the cold. An advantage to this type of drysuit is that you can use different thicknesses and types of undergarments to “tune” your insulation to the conditions at hand.
The insulating undergarments are available at your local professional dive retailer, and your instructor or dive professional can advise on the various styles and materials available.
When to Buy
Most recreational divers who dive in temperate regions buy their first wetsuit either during or shortly after their open-water training. A drysuit requires additional training and should only be purchased during or after taking a drysuit diver specialty course.
How to Buy
Because a wetsuit is an item of apparel and must fit well to work well, it helps a lot to be able to try the suit on before you buy, and a local dive retailer can be a great asset in that regard.
Divers who are shorter than usual, taller than usual, body builders or otherwise outside the usual size ranges can still get a wetsuit because some manufacturers will custom-make a suit to measurements made by your local dive-store professionals. But many manufacturers offer extremely wide size ranges. You may very well be amazed at what you can find “off the rack.”
Dive Suit Maintenance
Wetsuits should be thoroughly rinsed, both inside and out, with fresh water after each day of diving. At the end of the day, the suit should be hung inside-out to dry, and if the suit is going to be stored, it should be thoroughly dried – out of direct sunlight – both inside and out. To store a wetsuit, hang it on a broad-shouldered wetsuit hanger which is available at your local dive retailer.
Drysuits should be rinsed on the outside with clear, fresh water and dried before storage. To dry the inside of a drysuit, turn it inside-out to whatever extent is possible and allow it to dry at room temperature out of direct sunlight. Most drysuits come with bags in which they can be transported and stored.
The zippers on both wetsuits and drysuits should be kept clean and lubricated with a zipper wax (available at your local dive store). Drysuit zippers require additional care to be certain that they can seal out the water on future dives. Take great care of these special zippers and they will last for many years.
And just in case you are unable to fully dry a wetsuit before flying home, there are commercial antibacterial solutions in which the suit can be soaked at home.