Pillowing in wetsuit

[Spratman]

Greetings guys and gals!

I want to run a theory by y'all and see if this is the problem.

I just finished my cert dives on Sunday. Saturday, gauging by my pool experience, I loaded up with 40lbs....Well, I had no problem getting down to the platform! Second dive, I dropped four pounds and still seemed heavy on the platform, but had more difficulty getting to the platform.

Sunday, I dropped an additional two pounds, so my total was 34 lbs. and I had to swim like crazy to get down to the platform. But when I finally did get there, my bouancy was REALLY good!

Now, my question is if my bibs, which are too big between my knees and my ribcage, are billowing will the extra air cause me difficulties at the surface going down, and then compress enough to allow the weight to be correct on the platform? Also, when I was at 25 ft, I was golden. However, when I dropped to 35 feet, I started to sink like a rock! I'd add air and started to swim back up to 30 and I'd start heading for the surface again. My thinking was that the air in my suit started to expand and there was then too much air in my BC, overcompensating.

Does this sound logical? Should I get a smaller set of bottoms so it fits tighter around the hips?

Any help will be greatly appreciated!!

BTW, I dove in Cancun with a swimming suit and a boat. Cold water diving was a hell of a lot of work!! No wonder cold-water divers are the best around. I'm glad I part of that group!

Jack

 

[The Kraken]

Much of what you describe is caused by compression and decompression of the neoprene of your wet suit causing you to lose and gain buoyancy respectively.

Diving thick wetsuits presents a problem because you need additional weight to overcome the increased, inherent buoyancy of the wet suit at the surface. But once you hit about 13-18 feet the neoprene undergoes a significant buoyancy loss causing you to sink like a rock. Once you get to the bottom the necessary weight you needed to submerge becomes superfluous.

If you elect to forego the additional weight it requires to submerge, you'll have to "swim down" until your wet suit compresses.

The problem is that, when you surface after a long dive with a relatively empty tank, you'll become REALLY positively buoyant when you hit that point of compression/decompression.

Damned if you do, damned if you don't. Just one of those things you'll have to live with diving that rig.

the K

 

[Hank49]

Does this sound logical? Should I get a smaller set of bottoms so it fits tighter around the hips?

Any help will be greatly appreciated!!

BTW, I dove in Cancun with a swimming suit and a boat. Cold water diving was a hell of a lot of work!! No wonder cold-water divers are the best around. I'm glad I part of that group!

Jack

Me being only an imcompetent warm water diver...I would say you have it figured out. Either the air inside, or the neoprene is compressing at depth giving you good buoancy and expanding as you go up. This is the main reason I moved to the tropics. If you come to your senses and get out of the cold, you can take off the wetsuit and demonstrate the concept here.

 

[daval]

Thats why I love my Trilam suit.

 

[Boogie711]

Greetings guys and gals!

I want to run a theory by y'all and see if this is the problem.

I just finished my cert dives on Sunday. Saturday, gauging by my pool experience, I loaded up with 40lbs....Well, I had no problem getting down to the platform! Second dive, I dropped four pounds and still seemed heavy on the platform, but had more difficulty getting to the platform.

Sunday, I dropped an additional two pounds, so my total was 34 lbs. and I had to swim like crazy to get down to the platform. But when I finally did get there, my bouancy was REALLY good!

Now, my question is if my bibs, which are too big between my knees and my ribcage, are billowing will the extra air cause me difficulties at the surface going down, and then compress enough to allow the weight to be correct on the platform? Also, when I was at 25 ft, I was golden. However, when I dropped to 35 feet, I started to sink like a rock! I'd add air and started to swim back up to 30 and I'd start heading for the surface again. My thinking was that the air in my suit started to expand and there was then too much air in my BC, overcompensating.

Does this sound logical? Should I get a smaller set of bottoms so it fits tighter around the hips?

Any help will be greatly appreciated!!

BTW, I dove in Cancun with a swimming suit and a boat. Cold water diving was a hell of a lot of work!! No wonder cold-water divers are the best around. I'm glad I part of that group!

Jack

A few things, Jack... not having met you, take it with whatever salt you want, but it sounds like you're overweighted... and with 36 lbs, I suspect you are. I'm 6'4" and 225 lbs, and with a 7mm wetsuit, I need 24 lbs or so. The extra weight requires extra air in your BC. Extra air in your BC means extra dynamic instability, and things start expanding/compressing willy-nilly. As a new diver, this can be very tough to learn to work with.

There are lots of threads on here about finding the proper weight to work with... I won't beat that dead horse, but give that some serious thought.

 

[spectrum]

As mentioned the bottom line is at the end of the dive. You need to be negative enough at your safety stop to maintain it and to make an orderly ascent thereafter.

Everything you mention about getting down at the begining of the dive is secondary since if you are set-up right for the end of the dive you will get down fine with the weight of the air in a full tank.

Neoprene will compress and loose it's bouyancy as it goes deeper. That is by far the biggest reason for having a bouyancy compensator. Other wise since you and the rest of your gear changes bouyancy little (except the weight of air) you could do it all by managing lung volume. That's how it all started and some skilled divers still dive this way. The lighter tank at the end of the dive helps in surfacing to end the dive.

The classic bobbing with 500 PSI end of dive test is the most commonly mentioned method. By the end of the dive your suit is saturated and any trapped air has almost certainly escaped so you are getting your weight down to just what you really need.

With that weight set spend a few minutes at the surface for your suit to expell air and to wet out. Relax, make sure your BC is defalted and with a deep exhale you should go down, take shallow breaths until you pass the 10-15 foot depth (YMMV) and by then you may be adding short bursts of air to your BC to slow your descent as you clear your ears. Happy landing.

My wife and I just started diving and had no trouble getting our starting weights by doing the bobing test in the pool, eyeball level with water surface with an average lung volume. I then did the math to add weight for loosing .08 LB per CF of air and added total diver weight times .026 when we go in salt water. I can tell that we will get to drop some of this as we get better but we've had perfectly workable setups from dive 1.

Pete

Greetings guys and gals!

I want to run a theory by y'all and see if this is the problem.

I just finished my cert dives on Sunday. Saturday, gauging by my pool experience, I loaded up with 40lbs....Well, I had no problem getting down to the platform! Second dive, I dropped four pounds and still seemed heavy on the platform, but had more difficulty getting to the platform.

Sunday, I dropped an additional two pounds, so my total was 34 lbs. and I had to swim like crazy to get down to the platform. But when I finally did get there, my bouancy was REALLY good!

Now, my question is if my bibs, which are too big between my knees and my ribcage, are billowing will the extra air cause me difficulties at the surface going down, and then compress enough to allow the weight to be correct on the platform? Also, when I was at 25 ft, I was golden. However, when I dropped to 35 feet, I started to sink like a rock! I'd add air and started to swim back up to 30 and I'd start heading for the surface again. My thinking was that the air in my suit started to expand and there was then too much air in my BC, overcompensating.

Does this sound logical? Should I get a smaller set of bottoms so it fits tighter around the hips?

Any help will be greatly appreciated!!

BTW, I dove in Cancun with a swimming suit and a boat. Cold water diving was a hell of a lot of work!! No wonder cold-water divers are the best around. I'm glad I part of that group!

Jack

 

[Canadian_Diver]

Thats why I love my Trilam suit.

Amen to that!

 

[Spratman]

I LOVE diving the Carribbean!! That was the first thing I noticed, other than 30' to 50' viz. Largemouth Bass and Sunfish just are not the same as Blue Tang, octopi and Parrot Fish. I'm heading back to Cancun in Nov. and can hardly wait!! I wasn't hardly saying that warm water divers aren't competent, but there are a heck of a lot of dynamics that you don't have to deal with....

Me being only an imcompetent warm water diver...I would say you have it figured out. Either the air inside, or the neoprene is compressing at depth giving you good buoancy and expanding as you go up. This is the main reason I moved to the tropics. If you come to your senses and get out of the cold, you can take off the wetsuit and demonstrate the concept here.

 

[Hank49]

I LOVE diving the Carribbean!! I wasn't hardly saying that warm water divers aren't competent, but there are a heck of a lot of dynamics that you don't have to deal with....

No problem. " (teeth chattering) -k-k-k-k-kind of c-c-c-c-c-cold t-t-today....b-b-b-but at least w-w-w-w-we're b-b-b-b-b-better d-d-d-divers......". heh heh

 

[Spratman]

Thanks for the input.

FWIW, I am 6'1/250. I'm not sure how much that makes a difference with the weighting issue. Except for my second dive that was about 40 minutes and I actually was down to 500lbs, all the other dives were over 1200lbs at the end. I can't remember if I had an ascent problem with low pressure. I can remember that a emergency group ascent I had to kick to go up.

After the first two dives and hyperthermia, dive number three I flooded my suit before starting. So, I guess that took care of the residual air problem. My next set of dives is going to be getting this weighting problem straightened out. For me, I'm the type that will stay focused on my problem until I overcome it. Then I'll start having fun.

Believe me, forty pounds will get me down, but the dive cons I talked to thought I was way too heavy...Hmmm, I wonder if they meant FAT! Oh well....And when I realized that I had dropped to 62ft on the long dive and really had to work to ascend! Even adding air, then I hit the crossover point and headed for the surface.

Thanks for the compression lesson on neoprene. I knew that it compressed, I just had no idea how fast that it did it.

When I talked to my instructor about having to work so hard to get to the platform, he just told me to go hand over hand down the bouy line.....strange. If this is going to be a matter of experimentation, then I guess I need to add some more weight and use an empty tank.

I know there are peak performance classes, but are you tuning your own equipment or just spending more shekels for something that is not useful information.

Lastly, if there are other warm water denizens that would like to invite me to change my mind, I'm more than willing!!

Jack