Time to Replace that Old Wetsuit?

Water conducts away heat about 25 times faster than air. Since we rarely dive in water at the same temperature as our skin, no matter how much epidermal fat - natural insulation -- you might carry, eventually you will get cold. Besides staying warm, there's another reason to wear some coverage, as I reflected when I lay in a hospital bed in 1999 while doctors considered amputating my right leg!

A dive suit will protect you from the slings and arrows of misfortune and what I call man-eating plankton, what some in the Caribbean area call 'sea itch.' I had snagged my ankle on something, probably coral, while wading out to a liveaboard's tender without my shoes on. It was not a cut, just an irritating abrasion, so I covered it with Vaseline and went diving for the week.

A month later, a hematoma appeared on my lower leg. I continued to travel and dive, but my leg didn't get better. Eventually, another more massive hematoma appeared, my leg became twice the size, and my lymph glands were working overtime, signs of a serious infection. Surgery under full anesthesia and time with drip antibiotics saw me eventually recover, left with nothing more than the scars. So that's a good reason for wearing a suit whenever you're in the sea.

Our senior editor, Vanessa Richardson, had been renting ill-fitting and smelly wetsuits on dive trips, but decided to spring for her own. With all the styles, thicknesses and qualities to choose from, not to mention price ranges, her research will guide you if you're ready to replace your old ill-fitting, smelly wetsuit.

The Material

Of course, you should buy a wetsuit designed for scuba, but some divers who surf might be tempted to seek a surfing wetsuit for double duty. They are cut for maneuverability and comfort, but their neoprene compresses at depth, so they lose buoyancy and insulation. Modern neoprenes are so flexible that scuba wetsuits have become much more body hugging, making them both more efficient and more flattering, even if you've developed a body like a bag of chips.

Chris Moleskie, CEO of Wetsuit Wearhouse in Williamsport, MD, explains that the ideal wetsuit is made of gas-blown neoprene, the highest quality because it's infused with thousands of tiny nitrogen bubbles that insulate you from the cold. While it will compress and eventually wear out, as all neoprene does, it is the most durable. A chemicalblown wetsuit feels softer but will not be as durable."

The Inside

Most wetsuits have a standard nylon lining, but some augment this with technology for a warmer effect. Pinnacle Aquatics touts that the merino wool lining of its wetsuits reduces water movement inside the suit, and it's incompressible, therefore, unaffected by depth. You might see them for sale at online sites like LeisurePro and Scuba.com in the $300-$400 range. But, you need to try to a suit for fit before you but it, because 'fit' is everything.

Jason Schmitz, a sales person at Dolphin Dive Center, mentions another high-end lining, titanium, which is either woven into the wetsuit or put between the neoprene and the nylon interior lining. He says, "It reflects body heat, reflecting it back to the diver, instead of through the neoprene and into the water, so it does keep you warmer. And it's easier to put on. But the con is if you bend and crush it, it degrades easier. And it's more expensive." Few divers notice the difference in performance since so little titanium is used. It's probably more a marketing tool than a noticeable benefit.

The Thickness

Fit and thickness are the most important factors for staying warm. Every body is different, but for the Caribbean, many people use 3-5 mm suits for water temperatures in the 70-85 degree range. The 5-7mm wetsuits are for water temps between 60 and 70 degrees. One possible rule: the older you are, the thicker the suit you will need. Another thing to consider: how much body fat you have. "The more body fat you have, the more insulation you have," Schmitz says. "I'm a skinny guy, so I need more layers of insulation."

Putting a shortie on top of a close-fitting wetsuit will provide more warmth in colder conditions, and if it's too warm, well, few ever called a dive because they were too hot underwater.

Schmitz (Dolphin Dive Center) says a 7mm to 8mm is best for places like the Galapagos or Northern California. What's most important is the core layer, and keeping your torso warm. That's why some wetsuits have two different thicknesses on different parts of the body -- a 5/3 mm wetsuit thickness means there's 5 mm on the torso and 3 mm on the arms and legs. For standard wetsuits, Schmitz recommends adding a sleeveless hoodie to warm the core layer or a neoprene vest or tee with sleeves, plus a hood for colder waters.

A two-piece combo -- often called a Farmer John -- of which each part is 7mm, means you could potentially have 14mm covering from neck to thighs. It might sound great for diving in Monterey or Carmel, "but that's a lot of flotation, so you'd need more weight," Schmitz says. "That said, in temperate waters, you want at least 7mm on your core."

A lot of heat loss occurs while bareheaded, although some argue about this. Hoods certainly add to your insulation and can be bought in 3mm, 5mm, and 7mm thicknesses. We knew of one diver in the Caribbean area who dives with a hood and very little else.

The Stitching

Besides thickness, stitching determines how long the seams and suits last. Moleskie of Wetsuit Wearhouse explains: "The cheapest, least strong seam is a glued stitch. It will sometimes have a piece of tape glued over the seams, which helps with comfort, but it will probably give out the quickest.

"Another basic stitch found mostly in 'bargain' wetsuits is the overlock stitch, which joins the neoprene at the seams by stitching the edges together. The ridge is on the inside of the suit, which can become uncomfortable. If this seam is stretched to its limit, it may let in some water.

Schmitz recommended looking at wetsuits that have weld tape covering the stitches. "The tape covers the threads, which means theyhave less abrasive and rubbing on them."

"At the other end of construction quality is the blind stitch -- the material is first glued and then stitched on one side. However, the stitch doesn't pierce the material, which would give an entry point for water. The blind stitch is then done on the reverse side and interlocks with the first stitch. That gives the strongest seam. It's found on the more expensive wetsuits."

Some suits use high-tech materials that are not neoprene. Lycra skins offer no insulation. Sharkskin and Fourth Element Thermocline figure-hugging suits are the equivalent of 1mm in neoprene. They can be worn under the wetsuit for a light boost in warmth or under a shorty for protection against abrasions.

The Fit

A snug feeling is normal. As long as you don't have trouble breathing, you can assume your suit is not too tight (it it's too tight, a wetsuit restricts blood flow, not good if you have poor blood circulation, and may obstruct off-gassing.) A suit too loose lets water flow freely through your wetsuit and doesn't feel good especially in colder waters and under the arms. Women's suits have narrower shoulders and broader hips than men's do, and extra room built into the chest for a proper fit. The suit should fit snugly at the wrists and ankles, with no gaps for water to seep in, and the neckband should be snug, but not tight enough to keep you from breathing normally. And, move your arms and legs up and down to make sure there are no gaps in the underarm or crotch area.

The latest super-flexible neoprenes fit well and are easy to get in and out of. Aqua Lung touts its AquaFlex as having three times the stretch of standard neoprene, eliminating the need of ankle and wrist zippers (two sources for water exchange and heat loss), and still making it easy to get in and out of them. At $329, it's not inexpensive. That said, the more expensive suits are usually more comfortable, less restrictive, and they give you more motion and flexibility.

Heavier-weight suits tend to be called semi-dry although they are really semi-wet. Seals at wrist and ankle, behind the zip and at the neck reduce the chance of water flushing and make the perfect body fit less of an issue.

The Maintenance

After diving, throw your suit into a bathtub with a little wetsuit shampoo or any detergent, rinse and hang it to dry in the shade before storing. Schmitz notes that it "must be completely dry, so that no mold or decay forms, or else it starts to smell." Suits dried in the sun can lose their insulation because the nitrogen in each bubble of neoprene expands and leaks out, effectively making the neoprene thinner.

Most of the physical abuse a wetsuit takes comes from divers sitting on their knees above and under water, which could compress and decompress the neoprene quicker than normal. But the common rating for wetsuits is 200 dives. "Most people don't dive that much," says Schmitz. "The max for an average diver is less than 50 dives a year, so a well-made wetsuit could indeed last you a lifetime."

- John Bantin & Vanessa Richardson