I found this on some
Canadian Wakeboarding School site and think it is the best description of the various drysuits that I have found...
There are three styles of drysuits that we sell. The Baggy Style, so called because of their baggy fit, like the Bare Ultra Dry and the O'Neill Boost. The Neoprene Style, a rugged all neoprene construction, like the O'Neill Fluid. And the Hybrid Style, which combines the baggy and neoprene to create an, increasingly popular, blend of both types.
Baggy Style Drysuits: Have been, by far, the most popular style of surface drysuit. This has been the case because they are very flexible in their use, fitting the widest range of body shapes, allowing lots of layering of clothing underneath to cover a wide temperature use range as well, and because the average store only stock this one style of suit, so people don't get to see the other choices. The baggy style drysuits, like the Bare Ultra Dry (our #1 selling drysuit) and the O'Neill Boost (the 2nd best seller), are reliable, well made, and have proven track records.
If you are tall and slender or short and very stocky, you'll have a tough time getting a good fit with a Neoprene or Hybrid style, so baggy is the way to go. Most women also go with the baggy style for a couple of reasons. Women tend to be more slender at all the seal points, the neck, wrists and ankles, so the baggy suits, especially the Bare Ultra Dry, with all latex seals, prove to be more water tight, keeping them dryer than the Neoprene or Hybrid styles. A lot of women tend to get cold easier, and therefore like to add extra layers of clothing under their drysuit to keep them warm and the baggy style suits are ideal for this, with their loose fit.
Bare Ultra Dry compared to O'Neill Boost. Both are great suits but there are some small differences between them. First of all the Bare is a bit less money than the O'Neill so that give it a small price advantage. The Bare's "Nex-Gen" material is super flexible and very easy to move around in, while the O'Neill is just a bit stiffer material, it is also a bit more durable. On this issue big strong types won't care about the difference while smaller, less muscular people may prefer the more flexible Bare. The Bare uses latex seals at all the openings, while the O'Neill has latex at the wrists and ankles but uses a neoprene neck seal. This means the Bare will be more water tight at the neck seal, however many people with larger necks find the neoprene seal more comfortable. Having said that, the neoprene neck seal can not be trimmed back to create a looser fitting seal while the latex seal can. Just a note of caution here, we get lots of phone calls when people try their new drysuit on in their living room, saying that there's no way they'll be able to stand the tight neck seal. We always say to trust us and go actually use it on the water before coming to any conclusion and 90% of them admit they don't even notice the tightness while they're out there using the suit. Finally, the O'Neill Boost does have a cool built in suspender, while Bare uses an elasticized waist band. Not a big deal for most people but if your a stock build, and need to go up a size to fit your chest or stomach properly, advantage O'Neill, because you can adust the suspenders so that the crotch of the suit is not hanging down around you knees.
In summary, assuming price is not an issue, these are two awesome suits and most people could go either way, with the Bare favoring ladies and more slender builds a bit and the O'Neill have a small advantage for stocky folks. Please remember, as I mentioned a couple of days ago, you can trust O'Neill's size chart on the Boost and most people will go one size smaller than the size chart suggests.
Neoprene Style Drysuits: All neoprene drysuits, like the O'Neill Fluid, look a lot like a regular wetsuit with their all neoprene construction. Of course they have a zipper across the back shoulder area so you can climb in and seal out the water, just like other drysuits. They are designed to fit snug from the waist down, like a full length wetsuit, and a bit baggier in the upper half so you can put a shirt underneath. With this style of suit the suit is thick enough (usually 2 or 3 MM thick) to keep you warm without the need for additional clothing, and unless it is brutally cold, most people just wear shorts and a t-shirt. Although I'm in the minority of drysuit users, this is my personal favorite style. I have an old sweatshirt that I cut the sleeves off about 3/4 of the way down, and it works great underneath. Some people don't bother with any kind of shirt but you can get a bit sweaty and the shirt will mean you don't have to wash the suit out as often.
There are several advantages to this style of suit. Being snug fitting, there is less drag on deep water starts. Not a big deal for most boarders but any slalom skier who struggles with their starts will appreciate it and if you've never used a drysuit before, they all add a bit of drag, just less with a snug fitting bottom half. A lot of people find this style of suit more comfortable, and I don't think there is any doubt that the neoprene seals are more durable, far less likely to tear or crack, and require almost no maintenance. So why am I in the minority preferring this type of suit. Well there are disadvantages as well. The neoprene seals rarely keep you as dry as the latex seals, as I mentioned before you trade off comfort for water tightness. Many people also find it easier to get in and out of the baggy style suits although I think there's not a lot of difference. Probably the biggest dissadvantage is that you need to be of average build because you have to fit the suit exactly to your body for it to seal up properly. This means if you're long and lean or short and stocky, or want to share the suit with someone a couple of sizes different than yourself, it's unlikely you'll get a decent fit, and since the suits are built for men's frames, most women will not get a decent fit either.
Hybrid Style Drysuits: As the name suggests they are a combination of a snug fitting neoprene bottom and a loose fit baggy top taped and glue together above the waist. Bare has been making hybrid suits with their Tech Dry and Polar Heat models for years, however since O'Neill introduced their Assault Hybrid a year and a half ago, there has been a big upserge in sales. The idea is of course to give you the best of both worlds, a warm, snug fitting bottom with durable seals and reduced drag, and a flexible, easy to move around in top that you can layer clothing underneath according to the demands of the weather.
Now, although these three suits are all hybrids, each is unique in it's own right. The main difference are in the type of seals and the thickness, therefore temperature use range, of the suits.
The Bare Polar Heat is the warmest and most bullet proof of the bunch, also costing a bit more that the other two. It uses a 5 MM thick lower half with a baggy upper and comes with a very nice 14 ounce, removable fleece liner to keep you toasty warm. These suits are especially popular with windsurfers, kiteboarders and surfers who are out there for extended periods of time in pretty cold water, like the north Atlantic off the northeastern US coast. The Polar Heat has neoprene leg seals with an inside gasket to help stop water from shooting up your legs and comes with velcro leg straps which can be used, or not, to further reduce the risk of water seeping in. In the baggy upper half of the suit it uses latex seals at the wrists and a trimmable latex neck seal. Like an all neoprene suits the Polar Heats needs to fit properly but Bare offers several non-standard sizes to help get the right fit. The disadvantages are few but some people will not be able to get the fit the need with this suit, because of the thickness there is a small trade off in freedom of movement and when things warm up you can overheat in this suit.
The Bare Tech Dry is the next level of warmth and durability. If you can imaginge using a 3 MM thick farmer john (full length sleeveless wetsuit) and then adding a water tight baggy upper shell, that's what the Tech Dry is. These suits are most popular with slalom skiers who are chomping at the bit to hit the water as soon as the ice melts off and want to ski late into the fall. The Tech dry also has neoprene leg seals with an inside gasket and comes with velcro leg straps. In the baggy upper half of the suit it uses latex seals at the wrists and a neoprene neck seal. Of course fit is important and Bare offers several non-standard sizes to help get it right. Again some body styles will not be able to get the fit they need but for those who can, this is an awesome suit.
The O'Neill Assault Hybrid is the most affordable, light weight and flexible of these three hybrid drysuits. It's like the drysuit for when it's almost warm enough you don't need a drysuit. The Assault uses a 2 MM neoprene bottom taped and glued to a breathable nylon upper. It uses neoprene neck, wrist and leg seals for maximum durability and comfort but you do trade off staying 100% dry for comfort. It is a great suit for folks not in the frozen north who want something comfortable and a bunch warmer than their full length wetsuit. The only other disadvantage to this suit is its limited fit as it only comes in standard sizes to fit more of the slightly taller than average build from XS to XXL.
The O'Neill Boost, and Fluid, as well as the Bare Tech Dry use a long neoprene neck seal, sort of like a turtle neck. With this type of seal, it is intended to be folded inward (the oposite way from a turtle neck shirt) with what would otherwise be the outside surface, folded so it's against the skin to give you the most water tight seal.