Drysuit course - Warm vs Cold waters

[ScubaSamScubaStevesFather]

As a tech diver, I will be taking a drysuit course in backmount doubles, and I can't decide if I should do the course in Tulum/PDC (I'm cavern certified) or a far and expensive drive away from me in a cold lake.

I plan to dive dry in US NorthEast and NorthWest (~45-55 degree temps) cold water, therefore it would make sense to learn the drysuit in cold water with my 150g thinsulate undergarment, however I would really prefer to just do my drysuit course in Mexico (with only a base layer) so I don't have to deal with that trip. My concern is that if I learn in Mexico, then when I incorporate my thicker undergarments it will be a problem for me.

Does the amount or type of undergarment have that big of an effect when learning to dive dry, or is it small enough where after learning how to use a drysuit I will be able to use those skills across all garment types?

 

[Badger7]

Going from just a thin pair of merino wool undergarments to multiple layers or a thinsulate suit doesn't really change the skills, but it does substantially effect trim and bouyancy. If you dial everything in wearing thin undergarments, you'll definitely need to work on both back home when using thicker undergarments, but the lessons learned would be completely applicable. You're still going to have to remember to connect and check your inflator hose, add air on descent to prevent squeeze, manage the bubble, dump air on ascent, know what to do if you get too much air in your legs, etc.

If you want to take a trip down to MX, do it, absolutely. Knowing that you'll have to figure out where to add some extra weight, reconfigure your trim, and deal with a little more gas in the suit when cold water diving back home doesn't sound so bad to me either, just make a friend that wants to split the gas and ride shotgun on that drive to the cold lake this spring too.

 

[inquis]

Most of the "learning" happens after the class. During class, you will be going slow and trying to be attentive, and probably succeed (conscious competency). After a few dives at home, you will feel like you "got it", and it will get out of control -- it's normal.

TBH, a 150 gsm undergarment isn't terribly thick and will be comfortable in Mx waters. (Dry land in the summer will suck even with thin layers, so just get wet right after suiting up.) You will always be able to pick up cold-water tips from your local dive buddies.

 

[flymolo]

mobility and dexterity will definitely be harder once you go back to diving colder water with thick undergarments and dry gloves (or thick wet gloves), but you'll adapt. i'd probably just do it in mexico because (with the exception of a few instructors) i think the quality of instruction is better down there

 

[crofrog]

I plan to dive dry in US NorthEast and NorthWest (~45-55 degree temps) cold water, therefore it would make sense to learn the drysuit in cold water with my 150g thinsulate undergarment, however I would really prefer to just do my drysuit course in Mexico (with only a base layer) so I don't have to deal with that trip. My concern is that if I learn in Mexico, then when I incorporate my thicker undergarments it will be a problem for me.

A 150g/sm thinsulate undergarment isn't even close to warm enough for 45-55 degree water. Most people in that temperature are going to be diving ~400g/sm thinsulate + some base layers + heat for the bottom of that temperature range.

For 45f water I'm in Halo Ar's which are similar to 400g/sm thinsualte + 200g/sm thinsulate heated vest + J2 base layers. You'll still start to get chilly after 1-2 hours.

Does the amount or type of undergarment have that big of an effect when learning to dive dry, or is it small enough where after learning how to use a drysuit I will be able to use those skills across all garment types?

Thinner undergarments are easier to learn how to dive than thicker ones. The thinner ones hold less air, and you can feel the squeeze a lot easier that helps you understand where the bubble is, and are much less constricting but you're not going to leave a class and be like "I totally got this drysuit diving thing."

You'll be able to spend way more time in the water with an instructor practicing in 76f water in Tulum than you will in 45-55f water up north, and you won't need dry gloves.

 

[landphil]

Unless you know that your dry suit instructor is awesome and going to spend a lot of 1-1 time to help you with weighting and trim, you’ll leave your class with the same set of minimal (but essential to learn) skills no matter where you take it. It’s the next 20-50 drysuit dives that are going to get you actually dialed in.

Really the only advantage to taking the class in cold water with a thicker undergarment is that you’ll have less bruising from those couple of times that you way over dump your suit and get super squeezed

 

[grantmac]

Biggest difference will be the gloves and slightly slower venting.
Worth asking any instructor if they teach buoyancy control using just the suit or split between suit and wing.

 

[JoeTPhilly]

I think you got great information from all the posters but just wanted to chime in because I was basically in the same situation and ended up doing the drysuit primer in warm weather. I found it nice to learn without having to deal with the issues presented by heavy undergarments, gloves and a hood. Also, I was also able to get in more dives since I was on vacation for the week. At home, I started to dive in cold water and each dive is a learning experience. For me, the hardest part has been ascents; gas just doesn't seem to want to vent from Thinsulate. I think you will be fine doing it in Mexico and then continue your training in cold water when you get back home.

Also, as to 150 gram thinsulate undergarments. That is what I use and was always cold at those temperatures. I added a Fourth Element X-Core vest and that helped a lot. However, it was a bit of an adventure when the doubles were low on gas and I didn't think I needed any additional weight for the vest. LOL

 

[crofrog]

For me, the hardest part has been ascents; gas just doesn't seem to want to vent from Thinsulate.

One of the "misunderstandings" I had with thicker undergarments earlier on was feeling like they're slow to dump. The hold onto more gas because they're lofted. The lofting is what keeps you warm.

I just started diving with more weight, and stopped trying to get as much gas out of them. I feel like I vent more frequently, but less. If you try to dive them like thinner fleece undergarments they take forever to dump.

My recommendation for doing a weight check is to go down to ~20ish feet. Loft your suit up so that any extra gas starts spilling out of the valve, then without going through a whole bunch of crazy motions and arm pumping just roll to the right, drop your legs and lift your shoulder, and let whatever gas wants to come out, out. Then ascent to 10ft and do the same dumping procedure. That's a good simulation of ascending from deeper and keeping the suit more lofted, and do your weight check like that. Much easier if someone is there to hand you weights.

I added about 10lbs compared to trying to get every ounce out of the suits, and got warmer, better control because I wasn't fighting to get gas out of the suit, and more comfort because of less squeeze.

 

[JoeTPhilly]

One of the "misunderstandings" I had with thicker undergarments earlier on was feeling like they're slow to dump. The hold onto more gas because they're lofted. The lofting is what keeps you warm.

I just started diving with more weight, and stopped trying to get as much gas out of them. I feel like I vent more frequently, but less. If you try to dive them like thinner fleece undergarments they take forever to dump.

My recommendation for doing a weight check is to go down to ~20ish feet. Loft your suit up so that any extra gas starts spilling out of the valve, then without going through a whole bunch of crazy motions and arm pumping just roll to the right, drop your legs and lift your shoulder, and let whatever gas wants to come out, out. Then ascent to 10ft and do the same dumping procedure. That's a good simulation of ascending from deeper and keeping the suit more lofted, and do your weight check like that. Much easier if someone is there to hand you weights.

I added about 10lbs compared to trying to get every ounce out of the suits, and got warmer, better control because I wasn't fighting to get gas out of the suit, and more comfort because of less squeeze.

Thanks. I will give it a try because I have been trying to squeeze out every bit of gas and dive with the least amount of weight.