Ok, so the title is a little misleading. There really is no such thing as the perfect wetsuit. But many manufacturers have come surprisingly close. With almost a hundred years of design expertise and trial and error, they’ve had lots of practice.
Whether you want a wetsuit, semi-drysuit or drysuit, will depend largely on the area you dive in. Wetsuits help keep your body warm in moderate temperature waters, while drysuits are for colder water dives like in Finland. Depending on your budget, you may want one of each. You should also ask yourself, do I actually need a wetsuit.
Warmer areas also leave open the option of having a full wetsuit, with full length arms and legs, or some kind of a spring half suit. A spring suit has shortened arms and/or legs. There are all different combinations and sizes. Some have bicep length arm sleeves or even a shoulderless, torso-only design. Some have full length arms, but mid-thigh length pants. If you dive in a very warm water, wetsuit might be an overkill. You could just use a good pair of board shorts and a bodyguard shirt to keep your warm.
Shorties cover the torso but have short arms and legs. Steamers cover all but the head, feet and hands. A convertible is a steamer with removable arms or legs.
Whatever the design, all suits are measured by the thickness of the neoprene material. A suit designated 3/2 is one that is 3mm (1/10th inch) thick in the torso, 2mm in the arms and legs. This spec works well for dives in water that is 60F (15.5C) or above. For more warmth, get a thicker suit, such as a 4/3. Some have three numbers – for torso, arms and legs.
As with other sports clothing, fit is important. A wetsuit needs to be flexible enough to allow easy movement under the water, without chafing or binding. A free range of movement is especially important in the shoulders since you’ll be using your arms to navigate. Snug is good, squeezing is not. If blood flow near the surface of the skin is restricted, you’ll get sore and fatigued quickly. That cuts short your dive time. Not what you paid for.
Some seams are glued, others are welded or even unibody. However they’re made, a secure suit will have good seams and the fewer the better. Splits in the material are more likely to happen at a seam. Also, a seam that isn’t made well can introduce sore spots. A suit can also be less flexible at the seam if not manufactured correctly.
Seams are inevitable in some designs, such as when the wetsuit is made with extra features. Removable headgear, integrated knife holders, hydrolock collars, fireskin linings for wicking… the list of innovations in modern suits is endless. But a well made suit will have the smallest number and the most ‘seamless’ seams.
Drysuits take the design one step further to enable divers to comfortably and safely dive for long periods in colder weather. Cold water, even as warm as 50F (10C) can kill an adult within minutes. Having a good drysuit under cooler conditions is imperative. Drysuits have attached booties to seal off the feat, as well as watertight seals around the wrists and neck. They’re worn with thermal underwear and the sealing keeps it dry, while the wicking of the underwear keeps moisture off the skin. A standard wetsuit allows a layer of moisture that is warmed by skin.
Take your time and try on lots of models in order to get the one that fits and moves as near perfect as possible. A good wetsuit will last years, so it’s worth taking the extra time to get just the right one.