Wetsuits are made of neoprene, a special synthetic rubber that contains thousands of air pockets. That makes them lightweight, highly elastic and well insulating. They hug the body and fit reasonably well around the neck, wrists and ankles - everywhere the water might gain entrance to the inside of the wetsuit.
But wetsuits are designed to have some breathability. They work by trapping a thin layer of moisture between the skin and the wetsuit. The body easily heats that thin layer and the body and suit work together to keep it heated.
Wetsuits come in a variety of designs. Some of that variation is just for the sake of fashion. But other aspects are functional. Those encompass zippers, seams and sealing material around the openings.
The number and location of zippers is a compromise between the need to keep the wetsuit flexible and easy to enter versus keeping it well sealed from cold water entering.
Because the line along a zipper is always less flexible than the surrounding material, zippers are often not placed directly down the front midsection of the body. That would make them easier to get in and out of, but it leads to more discomfort for a surfer who is constantly leaning over or lying down to paddle, popping up and crouching.
Similar comments apply to any kind of seam. Though more flexible than a metal or even a plastic zipper, a joint where two layers of neoprene meet is always going to be less flexible than a large swatch of material. The glue is less flexible, if that's how the seam is sealed. But even a seam created by heat sealing will have some thickening, which is less flexible. Otherwise, it wouldn't be a seam.
As a result of these issues, designers try to maximize the comfort and stretch of a suit where it is most needed. Since wetsuit design is as much art as science, and everyone has a different viewpoint on the best design. So, there are hundreds of different choices.
Drysuits are a special category, needed only by those surfers who are braving the coldest waters. Whether in the UK, Alaska, or other areas, there are waters that are consistently below 60F/15C. It's possible to lose body heat to a dangerous extent. In most cases, that calls for a drysuit if the wearer is going to be exposed for more than a few minutes.
Drysuits, unlike wetsuits, are designed to allow no entry of water at all. They're made from a dozen different materials, but are often a form of neoprene as well. They tend to be more flexible, but are also often used with an undersuit as well, along with booties, gloves and a hood.
Let your personal comfort and the conditions you surf in be your guide. Always wear uv protective clothing and sun protection swimwear with UPF50+ maximum cover.
