Drysuit Basics

[dannobee]

Rob brings up some great points regarding switching from a wetsuit to a drysuit. With a limited number of dives under ones belt, the task loading of a drysuit can be daunting. A more experienced diver could be a lot more comfortable with their gear before switching. A new diver probably isn't even used to his "normal" setup yet and adding a drysuit can be overwhelming.

That said, in temperate or colder waters, it might be advantageous to incorporate drysuit diving into Open Water classes, much like it's done in England and Northern Europe, rather than "adding" it on to an AOW class. At least proper instruction and supervision would be incorporated into the class rather than some trying to learn it on their own.

When I switched to a drysuit I already had about 100 dives and asked my usual dive buddy (he's an MSDT) if I needed a class. We basically did some pool work, then did our usual dives with him emphasizing any drysuit specific changes and adjustments to diving.

 

[medic001918]

I would also recommend taking the course, especially with only 10 dives under your weight belt. You're still learning how to really control yourself in the water and the dry suit adds an entire other dimension to the dive that you need to be cognizant of. Your instructor should show you tips on caring for the suit, as well as pre dive and during dive suggestions. You'll learn how to operate your valves and how to control yourself should the unexpected happen (stuck inflator, tear, etc.) With limited experience, you'll find a lot of benefit to the course.

Shane

 

[Colliam7]

Obviously Boyancy will be the main issue but I also want to know what the major issues that might happen and put the diver in a risky situation.

As others have said, you have a second low pressure inflator valve, which can fail / stick in the open position, etc. Perhaps, an equally significant issue, related to safety, that will be addressed in a class will be management of the situation where the air in your suit moves to your feet and you go inverted. If there is excess air in the suit, and you go inverted, you may find yourself making an uncontrolled ascent, which is certainly risky. As several have noted, the vent valves on most drysuits are in the upper arm, so going inverted precludes you from venting excess air. You will learn techniques (tuck and roll) for getting out of the inverted position. You will probably also go over equipment strategies to minimize this from happening - use of neoprene socks instead of attached boots, use of gaiters, fin weighting, etc.

A secondary issue of safety, at least from my perspective, is ensuring proper fitting / trimming of the neck seal, so that it is appropriately watertight, without being too tight and producing carotid squeeze, and the associated consequences.

Have fun. Diving dry in cold water is wonderful!

 

[Divin'Papaw]

Welcome to SB cottonbroker! There are alot of drysuit divers in central Indiana. I don't have anything to add beyond what others have said. Just keep your first few dives shallow, simple and safe and then gradually extend your limits as you gain comfort. Keep and eye on the Great Lakes Wrecking Crew and Kentucky Piranha Patrol forums and come out and dive with some of us sometime. We dive at various locations in IN, OH, IL and KY on a regular basis.

 

[cottonbroker]

Thanks Jack

 

[cottonbroker]

Great Info, the more the better. I'll be looking for a class and be ready to practice.

 

[brutus_scuba]

1) Only put the mimimum amount of air into the dry suit to get the "Squeeze" off. The drysuit will not vent air as fast as a BCD so if you start ascending it is easy to have a rapid ascent (I had a rapid ascent from 25' to 10' in my first OW dive with the dry suit, scared the hell out of me). Then use the BCD for bouyancy control.

I have also been told the colder the water the more air you want in your dry suit to help insulate you from the water. Anyone else ever heard this or is diverrobs analysis what is taught by all the agencies and the way everyone here dives?

 

[DA Aquamaster]

I agree to a point - some divers dive really squeezed and then complain about being cold. That is a natural consequense of the undergarment not being fully lofted and all under garments rely to some degree on trapped air in the insulation to be effective. It is a matter of priorities. If you poll a bunch of experienced dry suit divers you will get a bunch of answers but the trend would probably be that the colder the water the more gas divers carry in the suit as cold becomes a bigger factor than managing a slightly bigger bubble. Ice divers in 35 degree water will give you a different answer than guys who dive dry in 50-55 degree water.

But all other things being equal you want enough to fully loft the under garment, but not so much gas as to make the bubble in the suit hard to control and reducing the volume to the point where you are just no longer squeezed is a good place to start. I tend to do that by defaulting to the slightly snug side and then add a bit more gas if things are getting cool.

 

[Divin'Papaw]

I agree to a point - some divers dive really squeezed and then complain about being cold. That is a natural consequense of the undergarment not being fully lofted and all under garments rely to some degree on trapped air in the insulation to be effective. It is a matter of priorities. If you poll a bunch of experienced dry suit divers you will get a bunch of answers but the trend would probably be that the colder the water the more gas divers carry in the suit as cold becomes a bigger factor than managing a slightly bigger bubble. Ice divers in 35 degree water will give you a different answer than guys who dive dry in 50-55 degree water.

But all other things being equal you want enough to fully loft the under garment, but not so much gas as to make the bubble in the suit hard to control and reducing the volume to the point where you are just no longer squeezed is a good place to start. I tend to do that by defaulting to the slightly snug side and then add a bit more gas if things are getting cool.

Well put. That is exactly how I dive. If I find myself getting cold, I'll definitely put a bit more air in the suit. I wear the Weezle Extreme+ undergarment and it requires loft to insulate. The colder the water or the colder I am from perhaps multiple dives or cold/windy surface conditions, the more I have to make sure it's fully "lofted". Even then though, I don't like a "floaty" feeling to the suit. I inflate it just enough to get rid of the squeeze, which can be quite painful, and to allow the loft of the undergarment to do its job.

 

[AirInHere]

I also just started drysuit diving this spring (14 dives so far).

I have been diving for just a year, and with the water temps here in Monterey holding between 45F to 54F, I was not going to dive often unless I used a drysuit. (I get cold easily).

Couple things I have already learned...

Drysuits are bulkier and inhibit your free range of motion a little bit mor than a 7mm wetsuit. Especially at depth when your suit is clinging tightly to your body. Sometimes I find I have to add air just to loosen the grip my suit has on me.

You have to really make sure you are not overweighted (or underweighted). Adding 2-4 pounds extra is not a huge issue, but if you carry 6-8 pounds (or more) extra, it is VERY difficult to maintain bouyancy. Take the time to really figure your weight needs!

Either decide to use the drysuit for bouyancy or the BCD. Do not waver back and forth. This seems easy, but adding air to account for squeeze and temperature compensation while using a BCD for bouyancy is tricky at first.

Expect your air consumption to skyrocket at first! Your air is going into your suit, BCD and your lungs. You are going to burn through some air untill you figure things out. Might want to wait on the nitrox diving utill you figure bouyancy out.

With a proper undergarment, you are not going to get cold unless the water is freezing! adding a little air does reduce the chill, but it also makes you more bouyant. Adding additional layers of clothes makes you more bouyant also. (See part about figuring out your weight requirements). This takes experience diving to figure out.

Chapped neck and wrists. Use baby powder. Apply between and just before all dives. Neck and wrist seals will give you a nasty rash. Nuff said.

You are going to have to take the time to learn about your own suit and really should always take a class oriented at familiarizing you with a drysuit. Afterwards, diving is the only way to figure out what you are doing in your suit. I would advise to try and dive with other drysuit divers so they can give you pointers as you get started and can answer questions you might have. Your air consumption rates are going to skyrocket at first, so expect your dives to shorten a little bit. Remember to avoid filling your suit and BCD at the same time for bouyancy. If you forget your BCD is partially inflated as you ascend, you could experience a runaway ascent. Rolling into a ball will not help you in that case.

Its going to be like learning to dive all over again. So start with easier dives and then work your way up to more difficult dives.

And wear 2 pairs of thick socks. Suit squeeze includes your feet.