wetsuit - drysuit - semi drysuits

[Carribeandiver]

Almost all of my diving, up to this point, has been in the warm carribean waters. But recently, I have discovered some colder waters and need more exposure protection.
A dry suit is an option but a DS has its negatives, such as price, movement restriction, requirement for undergarments, special fins to fit the booted up feet, etc.
Wetsuits are ok but only can provide so much exposure protection. Even a 7 mm isnt enough in relatively mild water if the dive is long enough.
And that leaves the semi-dry suit as an option. However, I know nothing about a semi-dry suit and they seem to be unpopular considering I dont see them being used and I dont see them being promoted by dive shops and online dealers.
Can anyone offer insights and tips on what a semi-drysuit is all about and also offer some tips on availability?
HAPPY EASTER to everyone

 

[The Kraken]

A semi-dry is a wet suit with baffles built into the suit slightly above the wrists and ankles to reduce the migration of water throughout the suit. Some have somewhat of a longer neck piece. Others have cape like shoulder covers that help reduce the speed with which the water enters the suit.

The suit, however, still relies upon neoprene to keep you warm, just as does a conventional wet suit. There are some semi-drys out there whose users report still having dry areas on their bodies after a dive.

Most of the better known manufacturers of wet suits will have semi-drys among their product offerings.

the K

 

[Mark Vlahos]

Think of a semi-dry suit as a really good wet suit. It will still allow water to get inside the suit, it needs to since it does not have a mechanism to introduce air, and without somthing you will get squeezed as you go deeper.

A traditional wet suit may allow a considerable amount of water to migrate through the suit. You will constantly need to heat the water with your own body heat to keep warm.

A semi-dry suit will have less water migration through the suit so you will need to heat less water. This will usually allow you to stay warmer longer.

A dry suit will hopefully keep you completely dry inside the suit. You wear undergarments of an appropriate thickness to trap a layer of warm air between your skin and the exterior material. You still need to heat this layer of air with your own body heat, but it will insulate you very well.

I have experience with a semi-dry suit and also a dry suit in water temperatures around the 50 degree mark. Both suits kept me warm enough to complete hour long dives in this environment. The HUGE difference is when you get out of the water. If you just made that dive in a really good semi-dry suit your body will still be wet when you get back on the boat. The action of the water evaporating will serve to cool you down. Whether the air temperature is warm or cold the water will still evaporate and your skin will cool. If you have just made the dive in a dry suit only the small amount of normal perspiration will serve to evaporate and cool your skin.

In short, in a dry suit you will start the second or third dive just as warm as you were when you started the first dive. If you have used a semi-dry suit you will start that second dive somewhat cooler than you were when you started the first. If you have used a traditional wet suit, you will probably start that second dive even cooler than you would have if you had made the dive in a good semi-dry suit.

For me, I rented wet suits for a while. Eventually I purchased a good semi-dry suit, and was happy for a while. Then I wanted to extend my diving season to the winter in Southern California so I rented for a while and eventually purchased a good dry suit.

Make your choices and get what will work best for you, and then dive, dive, dive.

Mark Vlahos