Wetter than a drysuit – drier than a wetsuit
Betwixt and between the traditional scuba diving wetsuit and the neoprene drysuit is a suit that captures the best of both designs. This suit is made for temperate to cold water where a drysuit is the preferred exposure protection for winter diving, and a 7mm wetsuit is the norm the rest of the time. Its design concept is a simple one. Combine the snug comfy fit of a wetsuit with the dry insulation of a drysuit. At the same time, eliminate the hydrodrag that is inherent in most bulkier drysuits, while getting rid of the heat-sucking waterflow that’s inherent in most wetsuits.
They call it the Semi-Dry, and as a category it includes a variety of models. At one end of the spectrum are suits that are more wetsuit than drysuit. They offer better water blocking features than most wetsuits but stop short of using the most efficient water-blocking seals and a drysuit-style zipper. At the opposite end are suits that are more drysuit than wetsuit. They have all the water-blocking features of a drysuit, including watertight seals at the neck, wrists and ankles, and, most importantly, a waterproof zipper. In fact, they offer virtually everything a neoprene drysuit offers except valves. And then there are a number of suits that fall somewhere in between.
Best Semi Dry Wetsuits by RDC’s Experts
The “More like a Wetsuit” Style
There’s lots to be said for this type of suit. They are substantially drier than a regular wetsuit, they are easy to get in and out of without assistance, and they are reasonably priced. The most effective design uses a horizontal zipper across the chest, an attached hood, and internal gasket seals to reduce water entry. The attached hood eliminates a major point of water entry—the neck—and a smooth-skin face seal keeps water from gaining entry via the hood. The wrist and ankles may have minimally effective O-ring type seals, but it’s the smooth-skin internal gasket seals located at the forearm and calf that keep water from seeping any further into the suit. (These gasket seals are sometimes called “flip seals” because the smooth-skin side lays flat against your skin while you are wearing the suit, but as you remove your arm or leg the material “flips” over, putting the nylon side against your skin for an easier exit.)
While the horizontal front-entry zipper on these suits is not waterproof, usually the zipper is designed with overlapping teeth that reduce water seepage. The zipper is also back-stopped with a neoprene dam that covers the shoulders to prevent direct contact of bare skin to any water that eventually seeps through. But probably the biggest advantage to this style of semi-dry is that you can easily open and close the zipper without your buddy’s help.
The “More like a Drysuit” Style
This style of suit is the answer for divers who like the “idea” of a drysuit, with the whole staying dry and warm thing, but when it comes right down to it, they don’t really want the additional bulk, buoyancy, and expense of a drysuit. These semi-drys, while they have almost all the features of a full-blown drysuit, fit snug like a wetsuit. Neck, wrist and ankle seals tend to be long sections of 3mm smooth-skin neoprene that can be folded under to create at least two or three inches of sealing surface against your skin. And the zipper is completely waterproof, just like on a drysuit.
While there are a number of semi-drys currently on the market, the following suits provide good examples of the semi-dry concept. Check them out.
Aqua Lung SolAfx 8/7mm
The SolAfx sits closer to the wetsuit end of the semi-dry spectrum. The torso is made from 8mm four-way-stretch neoprene, and the arms and legs are 7mm thick. The zipper has overlapping teeth with a tight tolerance to reduce water flow. A neoprene dam behind the zipper completely covers the upper chest and shoulder areas to prevent any cold-water shocks down the front of the suit. The seams are glued and blind-stitched, plus a new liquid weld has been added to the exterior to make the seams even more durable and waterproof. Gasket seals at the forearms and calves minimize any water that gets past your boots and gloves from moving into your core area.
The attached hood has a smooth-skin face seal, and a special vent that allows air to escape without letting water in. A built-in kidney pad helps fill the hollow in the lower back, and knees are well-protected with a Kevlar looking panel that’s built right into the suit.
Construction-wise, the exterior seam welds on the SolAfx can’t be overlooked as a major move to maintain the integrity of the seams and prevent leaks. And the way designers combined the kneepads with the lower leg panel rather than laying it over the neoprene really increases leg flexibility.
Getting in and out of the SolAfx is super easy with the wide mouth opening of the horizontal front zipper. Once inside you can really feel the thickness of the 8mm torso, 7mm arms and legs and the kidney pad. The neck/shoulder dam adds an extra layer of insulation and blocks any water that gets past the Plasmaloc zipper. The smooth-skin interior of the hood offers a two-inch-wide strip of sealing surface that felt comfy and kept the water out during our test dive. Lastly, the internal gasket seals in the forearms and calves kept water from gushing up the cuffs when we jumped into the mid-50 degree ocean. By the end of the dive we were wet, but the water had seeped in so slowly that we hardly noticed.
While it won’t keep you as dry as other semi-dry suits, the SolAfx keeps you a lot drier than a standard wetsuit. Plus it’s comfortable, easy to don and doff, and having an attached hood with a smooth-skin face seal not only keeps your head relatively dry, but it’s the best way to eliminate cold-water shots down the back, which in our book is the curse of cold-water diving.
Cressi Lontra 7mm
The Lontra gets you another step beyond traditional wetsuit diving. Made of 7mm Ultraspan neoprene with a plush inner lining, the wrists and ankles on this suit offer a double cuff similar to what’s found on some drysuits. The inner cuff is made of 2mm smooth skin neoprene that can be folded under to create a waterproof seal. The gloves and boots are worn over these seals while the zippered cuff fits over the gloves and boots. An adjustable 360-degree smooth-skin collar creates a decent neck seal. The horizontal rear zipper offers a long pull leash and finger loop at the base for easy self-zipping, and a smooth-skin underflap acts as a cushion between bare skin and zipper to increase comfort and cut down on water seepage. The Lontra’s separate hood has smooth sealing surfaces at both neck and face to keep water out. A double layer along the top of the hood offers offset holes to vent air. Shoulders and knees have anti-wear pads. All seams are glued and blind-stitched internally and externally.
Donning and doffing the Lontra is definitely made easier with the zippered wrist and ankle cuffs, although they do add a level of complexity that some of our test divers would have preferred to do without. The soft plush lining also helped the suit slip on with less effort, plus it created a cozy feel. The back zipper was easy to self-zip by pulling down on the base loop with one hand while pulling up on the zipper lanyard up with the other. We rolled the internal cuffs to create a drysuit-like seal, then pulled on boots and gloves and covered them with the outer zippered cuffs. It proved to be an effective system for blocking water entry. We didn’t feel any water moving up the arms or legs when we entered the 55-degree water. We did, however, feel water trickling in along the back zipper. The smooth skin neck seal did keep water from flushing into the suit and the sealing surface inside the hood did its job too. The kneepads seemed thin, but they covered a lot of leg area and proved to be flexible while kicking.
The Lontra is a comfortable suit that’s easy to work with. It does a really good job of keeping water out everywhere but at the back zipper. In our view, adding a strip of smooth-skin along one side of the zipper that could seal against the smooth-skin underflap would go a long way in minimizing water seepage in this area. Having said that, the Lontra already does a better job of keeping water out than standard wetsuits, yet you can buy it for less than what you’d pay for many standard wetsuits. So you can’t really lose with this model. Note: a 5mm hooded jacket for $169.95 is also available to further enhance the Lontra’s thermal and water-blocking capabilities .
Mares Isotherm 6.5mm
The Isotherm takes us to the drysuit end of the semi-dry spectrum. Mares designed this suit around their “Trilastic” philosophy, which is to bring different types, thicknesses, and flexibilities of materials together to fit both diver and dive conditions. Then they added a TiZip drysuit zipper and double smooth-skin seals at the neck, wrists and ankles. The inner seal folds under and mates against your bare skin to keep water out, while the outer layer sandwiches boot tops and glove ends to further restrict seepage. Plus they’ve added some small internal gasket seals higher up on the wrists and ankles and a separate drysuit-style hood with a smooth-skin interior, so a wetsuit can’t really get any closer to drysuit performance—without becoming a drysuit.
The Isotherm goes on easy due to its wide-open back entry, slick nylon lining and ankle zips, but you’re going to need help zipping up the TiZip zipper (although it turns out it is possible to unzip it by yourself once you get the hang of it). A soft plush material lines the torso for extra comfort. The neck and wrist seals performed as well as any drysuit seals we’ve used in blocking water entry. The ankle seals were not as effective, but we concluded that this was due more to fit than to seal design. The smooth-skin interior of the hood mated perfectly with the smooth-skin neck collar, blocking all water entry. The same held true for the hood’s face seal. The suit offers lots of lower leg protection because rather than sewing on kneepads Mares uses wear resistant material for the entire lower leg panel. The same tough material also protects the elbows.
The Isotherm is just about perfect when it comes to a semi-dry design. It’s one of the driest wetsuits we’ve ever worn. At the end of our test dive we still found large sections of bone-dry material, from knees to neck, when we pulled the suit off. We could have done without the zippered wrist cuffs, but that’s a personal nitpick. When you’re talking semi-dry diving, you’re definitely talking the Isotherm 6.5
Scubapro NovaScotia 6.5mm
Like the Isotherm, the NovaScotia lands on the “more like a drysuit” end of the semi-dry spectrum. Built out of 6.5mm nylon neoprene with EverFlex panels strategically placed in the high-stretch areas, the suit starts with a TiZip dry zipper and adds all the water blocking features you could ask for on a super-dry wetsuit. Wrists, ankles and neck feature 3mm drysuit-style smooth-skin seals that fold under to create a waterproof closure. Wrists and ankles have external cuffs that roll over boot tops and gloves to further restrict water flow, and the neck has an external collar to fit over the bottom of the vented hood. Thermo Plastic Rubber kneepad-type patterns have been applied to the lower legs and shoulders to provide a little abrasion protection in those areas.
They call it a semi-dry, and it’s at least that. After a full dive in this suit we were surprised to find our torso and arms virtually dry, and our swimsuit barely damp. It was only from the knees down did we feel truly wetsuit-wet. Of course, after the course of an entire day in the water seepage inevitably encroached, but it never got beyond the somewhat damp level in the torso area. And for a 6.5mm suit, it kept us surprisingly warm. After three dives in depths down to 90 feet and in water temperatures ranging from 48 to 53 degrees, this one-piece suit, without benefit of an undervest, kept us surprisingly comfortable.
Getting into this suit is easy with the large opening of the back zip. Hands and feet slip through the double sealing cuffs easily without the need for wrist and ankle zippers. The TiZip zipper does require your buddy’s help in zipping and unzipping. But overall, this suit is comfortable, and the seals and zipper are extremely effective in keeping water from getting inside the suit. The non-skid strips on the shoulders are good for keeping BC straps from sliding around, but the kneepads, while a nice-looking design, don’t look like they’d do much when it comes to knee protection.
The NovaScotia is a perfect example of the staying dry in a wetsuit concept. It turned out to be the driest semi-dry of the group, and it was right up with the rest of them in comfort. We’d like to see some better abrasion protection in the leg area, but that’s the only gripe we have with this suit.
This is a tough call. All of these suits are a little different, and they all have something going for them. The SolAfx is warm and comfortable, its attached hood and front zip make it easy to use, and it will keep you drier than your typical wetsuit. The Lontra will keep you drier still, it too is comfortable, it has great seals, and it’s less expensive than most standard wetsuits. For the ultimate in semi-dry diving you have the Isotherm and NovaScotia. They both really come through when it comes to keeping your warm and relatively dry, so which one you choose really depends on which one fits best, and what features you prefer.
I’ve been a diving addict since my 14th birthday when my parents took me to the Bahamas and had my first scuba diving experience. I’ve been an active diver ever since but in the last few years my focus shifted on sharing my thoughts and experience on diving gear, writing product reviews and gave up on organizing dive tours.