Tips For Staying Warm While Scuba Diving

BEAT THE CHILL
You’re in the ­tropics and your dive computer indicates the water temp is 80 degrees F, so why are you ­feeling cold? Like a lot of things related to diving, there’s probably no single answer. But in a nutshell, water robs your body of heat, and if you’re not taking steps to retain body heat, you might feel chilled, either at depth or during your surface interval.

“I think divers ­sometimes forget that we lose heat from our bodies much quicker in the water than we do on land,” says Jo Mikutowicz, managing partner of Grand Cayman’s Divetech. “Even though the air temperature might be very warm, the water can take the heat away from you 20 times quicker than in air.”

Dr. Petar Denoble of Divers Alert Network explains the physiological reasons. On land, when the air is cooler, “the body can limit the rate of heat loss to a certain point by physiological mechanisms, including bringing less blood to the skin,” he says. “Unlike the atmosphere, water has much greater thermal capacity and conducts heat away from your body much faster. Even swimming in a pleasant temperature will cause the body to lose more heat than it produces.”

The bottom line: You’re on your dive vacation to chill out, but feeling cold underwater is spoiling your fun. We asked dive pros to share their tips and advice for ­staying warm during a dive.

1. START THE DIVE WARM
You’ve checked your gear and reviewed the dive plan with your buddy, so you’re ready to dive, right? Not so fast — there are things to consider before you even step onto the boat or gear up on shore that can make you more prone to getting cold during a dive. “Starting out a dive already cold is not a good thing,” says Mikutowicz. “It will only go downhill from there.”

Take a moment while you’re still in your home, resort room or liveaboard berth to make sure you’re ready to dive. “The biggest mistake divers make that leads to getting cold is ignoring all the little things involved,” says Karl Shreeves, PADI technical development executive. “Don’t skip meals before the dive — don’t eat heavy, but fuel your body so it generates heat. To stay comfortable during the dive, stay warm before the dive; even if ­you’d be comfortable without covering up, cover up so it saves energy for the dive.”

2. DRESS FOR SUCCESS
Remember when you were a kid and stepped outside in shorts, a T-shirt and flip-flops even though it was starting to snow? Diving in a 1 mm skin in 72 degrees F water is the same thing. You’ll be shivering long before your dive computer tells you it’s time to end the dive.

Don’t wait until you’re at your destination to figure out how much neoprene you’ll need.

“Check the current water temperature of your destination before you leave home,” says Cayman Aggressor IV's Capt. Lauren Hill. “Even in the tropics, certain times of the year can get chilly.”

Divers on vacation favor a laid-back, casual wardrobe, but that is where dressing for success takes on new meaning. “One needn’t be able to explain the hypsometric equation to understand that thicker is better,” says Kell Levendorf, dive-accident investigator for Dive & Marine Consultants International. “Boardshorts and rash guards might be de rigueur for the younger professional crowd, but old-timers understand and appreciate the warmth and protection that a full suit provides. Even in the warmest summer months, I’m in a 5 mm suit that fully covers my arms and legs.”

And don’t be afraid to layer. “When the water drops even a couple of degrees, layer under or over your wetsuit to help keep your core warm,” says Liz Parkinson of Stuart Cove’s Dive Bahamas.

3. CHECK YOUR WETSUIT
So you’ve made sure your wetsuit is the right thickness for the water conditions, but are you sure it fits correctly and is in good condition?

“Basic improper fit, especially when combined with a loss of insulating thickness from constant wear, is the chief culprit,” says Levendorf. “This is a particular problem for divers wearing rentals. A wetsuit should be every bit as important an early purchase as a mask and fins. And just as properly fitted by a dive professional.”

Once you wriggle into your wetsuit, you should look like Rihanna going out for the night. A wetsuit that fits perfectly will be skintight and molded to your body. A loosely fitting one will be easier to get into, but it will leave gaps against your skin, especially at your neck, that will scoop up water. Before you know it, that sneaky ­culprit — H2O — will be ­stealing your body heat.

4. COVER YOUR HEAD
Lots of people don’t like wearing hoods, but it’s estimated that 20 to 40 percent of your heat loss is through your head.

A hood prevents heat loss, and if you attach it to the suit, it can also eliminate water that slips in via your wetsuit’s collar opening. Even better, says Parkinson, “add a hooded vest.”

And don’t forget about your hands and feet. “I don’t usually like wearing gloves, but if it’s really cool water, a thin pair of gloves helps,” says Parkinson. “Wear ­booties and adjustable fins, and save the full-foots for diving in tropical water.”

5. STAY SHALLOW
Check your computer on your next dive. If it registers water temperature, you’ll notice that the deeper you go, the further water temperatures drop.

Besides colder temps, however, the greater pressure at deeper depths also affects your wetsuit by reducing its insulating properties. This is because the insulating bubbles in the neoprene compress under pressure — you’ve probably felt the sensation of your wetsuit “hugging” you tighter as you drop deeper on a site. By the time you’ve reached 99 feet, the bubbles have practically completely flattened out — that means you’re now wearing a wetsuit that’s providing little insulation. Unless you’re exploring a deep wreck or wall, try to stay in the sunlit shallows.

6. WARM UP AT THE SURFACE
Once you’ve ended a dive, you’re wet, and as the water evaporates, it sucks heat out of your body. When it comes to your surface interval, the pros all agree: Get out of your wetsuit and into dry clothes. “In the tropics, it’s usually enough to peel your wetsuit to your waist and dry off,” says PADI’s Shreeves. “But in cooler climates, get entirely out of a wet wetsuit or neoprene drysuit.”

Says Parkinson: “Get dry, towel off, and dress. No matter if you are shore diving or on a boat, get out of the wind.”

If it is windy, says Aggressor’s Hill, “a jacket will help you avoid wind chill.”

If you take off your wetsuit, try to find a spot where it can dry. “Hang your wetsuit inside out,” says Aggressor’s Hill. “That way the inside of the suit dries first, which is the part that touches your skin when you put it back on.”

The surface interval is a good time to refuel. “Something hot to drink can help spike your energy levels,” says Parkinson.

7. DON'T BE A MARTYR
Sometimes, the best precautions aren’t enough. We’re not polar bears, after all. “Once you start to chill, there’s not usually much you can do underwater except end the dive,” says Shreeves.

Once you get that cold, diving is no longer fun. And you shouldn’t worry about ruining anyone else’s fun. “Communicate to your buddy that you’re getting cold,” says Parkinson. “Chances are, he or she is cold too.”

And if you do a lot of your diving in cold water, it’s time to consider a drysuit.

Read More: 3 Great Drysuits For Cold-Water Scuba Diving