Dry suits

[thewisestfish]

hi everyone,

Ok, this is a really basic question - and hopefully someone will be able to help me out.

Dry suits - what's the difference between neoprene and membrane. I've only dived in a wet suit, so dry suits are kind of alien to me. What's the crack with all these valves on them? I'm going to buy one definately - but I want to have a bit of an idea what I'm looking for, and what questions to ask before I do. The prices seem to vary dramatically too, and I'm not sure why. Oh, and finally, what do you wear under them (no rude suggestions....please) Do I have to buy some kind of under suit too...... HELP! Thanks.

[Helen F H]

I dive a membrane, simply because im a funny shape and it had a better chance of fitting me.

Membrane - like a waterproof jacket type material (only tougher). No thermal insulation properties, therefore you need a nice warm undersuit. Very flexible, but liable to get holes.

Neoprene - thick neoprene, excellent thermal insulation. However, has buoyancy changes at depth (as the wee bubbles get squashed). Not too comfortable.

Valves allow youto put air in, and let air out. Like a big BC.

[wilbo]

Originally Posted by thewisestfish

hi everyone,

Ok, this is a really basic question - and hopefully someone will be able to help me out.

Dry suits - what's the difference between neoprene and membrane. I've only dived in a wet suit, so dry suits are kind of alien to me. What's the crack with all these valves on them? I'm going to buy one definately - but I want to have a bit of an idea what I'm looking for, and what questions to ask before I do. The prices seem to vary dramatically too, and I'm not sure why. Oh, and finally, what do you wear under them (no rude suggestions....please) Do I have to buy some kind of under suit too...... HELP! Thanks.

A silly question is one that is not asked..

Membrane drysuit: a canvass bag (sometimes made from a slightly stretchy material). Very flexible. Non compressible - non change in material due to depth. In itself, offers no thermal protection. You will need some form of undersuit. Typically 200g or 300g for Uk waters, depending on time of year and personal comfort.

Neoprene drysuit: Made from rubberised material, containing air trapped into the material during manufacture. Compresses more and more the deeper you go, due to the trapped air. Therefore affects buoyancy and thermal insulation. Offers thermal protection, depending on the thickness of the suit. Undersuit worn is typically 100g or even just thermal clothes. Comes in two forms. Compressed and uncompressed neoprene. Compressed neoprene, does not compress under depth as much as uncompressed. Therefore starts to take on more of the characteristics of a membrane (less thermal protection, less affected buoyancy at depth, thicker undersuit needed etc) Similar to Wetsuit material. typically less flexible than a membrane.

The valves are for air in and air out.. purely for buoyancy (and to a certain extent insualtion from the cold water)

think that covers it..

[turbanator]

What Porg and Wilbo said.
A couple of extra points.
A big generalisation, but membrane usually have latex seals and neoprene have neoprene seals.

Latex seals, in my experance are drier, but are a lot more fragile and also rot quicker (due to being wet, salt, sunlight (UV), skinoils, suntan lotion).
However mebrane dries very quickly and can probably be fixed between dives.

It is possible to stick neoprene wrist seals over latex to protect then or latex under neoprene to get a better seal.

There is little or no stretch in a membrane suit, so it has to fit well, loose enough to allow freedom of movement, but not so large that you end up with a big bubble of air floating about.

Also consider front or rear entry zips.

Before you buy one, try different types.
BS-AC has a drysuit course, but it is now covered quite a bit in Ocean Diver training, I'm sure PADI have similar if you're that flavour.

This will explain a lot of the features of drysuits in general, and the diffences between the two. It will also give you a chance to have some pool sessions.

I've tried to be as unbiased a possible, but, personally, I use a membrane.

r
Paul

[Fathoms Down]

Yes, PADI also cover suit types, selection and operation on the Drysuit Speciality Course.

One suit that people haven't mentioned is the rubberised suits. These aren't common (I believe Gates do one) but are still available. They tend to be a bit like membrane suits but are made of a cloth like material dipped in rubber. They tend to be a bit tougher than membrane suits but are less flexible; a sort of middle ground between membrane and neoprene suits.

[Foggy]

Bear in mind that although neoprene suits are made from rubber (which conjures images of stretchy material in the mind) in my experience they restrict movement. I've had two, and neither would allow me to reach behind my head to shut off pillar valves (a DIR thing....but you may want to go that way), and I've had problems climbing ladders etc. You still need something underneath as the suit compresses it looses its insulation, I've used various underwear and the "dryliner" from Divers Warehouse is pretty good. However, these all act to restrict movement further, (nb. underwater there's no problem, it just that you're a beached whale when on the surface).

Valves are to get air in to avoid squeeze, then you choose whether you want to use the suit for buoyancy or not (that's contensious as each agency advises differently on this point, but the more things you have air in the more things you have to get air out of). Then there's a valve to get the air out, which can be a simple cuff dump - these never let me get enough air in the suit for buoyancy, and you can control the rate of release by raising your arm; or an auto dump (usally shoulder mounted) which is adjustable. I have had undersuit block these, so look out for undersuits designed to breathe where the dump valve is. Last ditch you can pull a sleeve or neck seal to let air out, but you get very cold as the water rushes in.

Membrane suits are baggier and allow a greater range of movement. With the undersuit being more insulating than for neoprene (not necessarily thicker, but usually so). I have recently converted to a membrane.

Undersuits I have usually got with the suit. NB there are often end of season sales at places such as DW if you don't mind secondhand.

I used to dive wet; in the UK I shall never dive wet again, and I consider it dangerous. My advice is to go dry. My advice would be to hire - I think both types are available, and if there is a potential sale involved I think you will get lots of co-operation....if you don't then take your hard earned dosh elsewhere. Finally, don't be rushed

Cheers, Paul

[Dominic]

Latex seals, in my experance are drier, but are a lot more fragile

And that's one of the great things about Otter drysuits - the heavy-duty latex cuff seals. Every time I come into contact with the standard seals now, I wince at how flimsy they seem..

and also rot quicker (due to being wet, salt, sunlight (UV), skinoils, suntan lotion).

Perfume-free talc, applied regularly, not only makes the seals a bit more comfortable, it soaks up the oils that would damage the rubber and prolongs the life of the seals. (Perfumed talc is useless, as the perfume is oil-based and will rot the seals.)

You can get oil-free suntan lotion, but it will of course wash off as soon as you get wet!

Also consider front or rear entry zips.

As opposed to crawling through the nexk seal, you mean?

Last ditch you can pull a sleeve or neck seal to let air out, but you get very cold as the water rushes in.

Bloke I was diving with at the weekend has no dump valves on his drysuit - lets it all out the neck seal.... can't say I'm tempted to follow suit tho (No pun intended)

[Mandlebrot]

Originally Posted by Foggy

I used to dive wet; in the UK I shall never dive wet again, and I consider it dangerous.

Please could you explain why you consider it dangerous to dive wet in the UK? or am I completely misreading your post?

Steve

[Foggy]

Diving wet in the UK (not semi dry) = cold = poor circulation (likely bend) = poor mental function, etc.

Surface interval = very F*****g cold

Second Dive = ......well lets be euphamistic....not enjoyable.

I used to do it wet in the summer down cornwall way, then I dived the N. Sea. And yes I did pee in the suit, but often I was too cold to pee (and it didn't do the suit any favours).

IMHO it is simply asking for trouble. NB only my opinion mind you.

Cheers, Paul

[wannadivenotwork]

BTW, not all Compressed neoprene suits have neoprene seals.

I have a ScubaPro Spitzbergen which comes as standard with latex sela, plus neoprene "covers" so that your gloves and hood can be enclosed between latex seal and neoprene. This helps protect the seals, but much more importantly it helps prevent water flushing from the gloves and hood.

But, the suit is fairly heavy, takes 5 years to dry out and restricts movement. Also, you have to be of fairly athletic physique to get into an "off-the-peg" number.

Love mine though. And the bonus is that it is techy/milk tray black.