Drysuit Weighting.

[Firediver]

I am diving in a 7mm compressed to 4mm neoprene drysuit. I am 5'7, and 145lbs. I am currently diving with 40lbs of weight.
At 15' I am ok, but when I am at depth I am too heavy and need to use quite a bit of air and work hard.... this makes me hard on air. When I was 35lbs, I had to fight to get down and stay down at 15ft during safty stops. Is there anything I can do to fix the problem so I am not using up so much air just to become neutral?????

 

[Groundhog246]

Did you jump all the way form 35lbs to 40? If you can barely get down with 35lbs, but you can get down, then another pound or two should be enough, not 5.

 

[crispos]

I am diving in a 7mm compressed to 4mm neoprene drysuit. I am 5'7, and 145lbs. I am currently diving with 40lbs of weight.
At 15' I am ok, but when I am at depth I am too heavy and need to use quite a bit of air and work hard.... this makes me hard on air. When I was 35lbs, I had to fight to get down and stay down at 15ft during safty stops. Is there anything I can do to fix the problem so I am not using up so much air just to become neutral?????

You should bend over at the knees and exhaust your suit of all air through the neck seal, before getting your BCD on.

That means the suit should be completely vented before trying to descend. Then, at depth, you can add air to get neutral (and warm).

A guy your size should not need 35 lbs of weight. Even in salt water. I would think 30 lbs adequate. Depends on accessories.

If this works, please teach me how to become a fire-fighter.

 

[sharkmasterbc]

I teach on the west coast of Canada and all our rental suits are neoprene. I have also had the opportunity to dive with people who have crushed neoprene suits. 40lbs sounds like a bit too much weight. As stated above you should only add 2-3 lbs to compensate for a nearly empty 80. What depths are you diving to ? I used to have a neoprene suit and had the same problem, I traded the suit for a bilaminate one with thermal undies and will never go back. The bouyency charesterics and the thermal protection remain the same no matter what depth you are at. I would hope you have a BCD with at least 40 lbs of lift cap. A friend had a neck seal go at depth on a neoprene drysuit (which was being used for bouyency), if he had a BCD with a few less lbs lift than what he was wearing there may have been a problem...To answer your question there is not much you can do about neoprene compressing at depth, see if you can try a "bag" suit, I'm glad I tried both before making up my mind.

You should hang a few weights at your safety stop on a line, with some sort of quick snap on them. Then if needed you can clip one on your BC and ta-da !! Also what are you wearing under your dry suit. We have found that different materials such as fleece and cotton have different bouyency.
Do a weight/bouyency check at the end of your next dive. Cross your legs, open your drysuit valve all the way (do the chicken wing thing to get all the air out of your suit) then deflate your BCD, if you breathe slowly in and out, you should sink on exhale and rise again on inhale.

 

[Groundhog246]

I thought of tha air issue re: initial ascent, but unless he's got it trapped somewhere (poor fit?), when he vents on ascent he should be able to pause at 15 feet. 35lbs does sound a tad high though, maybe he's got really thick woolies as well.
You should also note, he is a SHE.

 

[matt_unique]

I am diving in a 7mm compressed to 4mm neoprene drysuit. I am 5'7, and 145lbs. I am currently diving with 40lbs of weight.
At 15' I am ok, but when I am at depth I am too heavy and need to use quite a bit of air and work hard.... this makes me hard on air. When I was 35lbs, I had to fight to get down and stay down at 15ft during safty stops. Is there anything I can do to fix the problem so I am not using up so much air just to become neutral?????

With neoprene suits you don't squat down to vent air. If the suit fits properly it should be like wearing a wetsuit. Trilam suit users must squat down to vent the air. Anyway - when you descend you vent the air in your BC and in your drysuit at the same time. If you had any residual air in your suit (i.e. if it was not a great fit) it will be vented at that time. Next time you dive make sure you have vented all the air from both systems at the surface and gauge your descent. If you just barely able to descend then you need the weight you are wearing - if you sink fast try dropping a few pounds. 5 lb increments is usually too much. You can't avoid the air required at depth with a neoprene suit. The most important depth for weighting considerations is between 10-20'. You need to be able to maintain neutral buoyancy at that depth as a number 1 priority. If you are deep and a bit heavy, you can get neutral with air in your system. If you return to 15' for your safety stop, have vented all air, and you are still too light, you are in trouble.

I am of the school wear you use both your BC and drysuit for buoyancy control at depth. The more air in your suit the warmer you will be. Of course beyond certain depths it would be cumbersome to use only your drysuit for buoyancy so you need to offset this with air in your BC. When I am below 70' I stop adding air to my suit and start using the BC. You have to make sure you remember to vent both systems as you ascend.

I use the O'Neill 7mm neoprene suit. There are other threads that address the advantages and disadvantages of each type of suit. To address one example earlier in this thread - you would definitely rather have a neoprene suit over a trilam suit if you had a neck seal failure. When you have a critical failure in a neoprene suit you are then wearing a 7mm wetsuit. When you have a critical failure in a trilam you are now wearing a wind breaker

--Matt

 

[sharkmasterbc]

I'm sure if I were to have a seal go I would much rather have on a neoprene suit (especially if it fit well) you are correct that his suit turned into a "windbreaker" also the drag created from having a flodded suit was absolutly stupid, not that it adds more weight but try swimmimg while encased in a bag full of water...

 

[sharkmasterbc]

I'm sure if I were to have a seal go I would much rather have on a neoprene suit (especially if it fit well) you are correct that his suit turned into a "windbreaker" also the drag created from having a flodded suit was absolutly stupid, not that it adds more weight but try swimmimg while encased in a bag full of water...

His suit did not fit him well, since then he has bought a custom fit neoprene suit. There is something to be said about getting properly sized.

 

[Firediver]

You should bend over at the knees and exhaust your suit of all air through the neck seal, before getting your BCD on.

That means the suit should be completely vented before trying to descend. Then, at depth, you can add air to get neutral (and warm).

A guy your size should not need 35 lbs of weight. Even in salt water. I would think 30 lbs adequate. Depends on accessories.

If this works, please teach me how to become a fire-fighter.

Ground Hog: I had added only 4lbs, but these were soft plastic coated weights, and the saltwater started degrading the plastic. So I had a spare 5lbs lead weight which put me to 40lbs.

Crispos: I do vent before and after I have my BC on also. As for the firefighting visit: www.firegirl.webhop.net that's my webpage.

Sharkmasterbc: The drysuit is custom fit. it's a Abyss Explorer.

 

[Firediver]

He is a SHE I am a female anyway, I do vent coming up and I usually dive between 60-90' rare occassion passed 100'. I will try and remove 2lbs and go from there. I am using fleece for undergarment. Fleece shirt, base layer fleece pants from Kombi, and one pair of wool socks.. I don't think my undergarments are making a big difference in my bouyancy.. I have been using both my BC and Suit for bouyancy control. I can't change to a bag suit because I don't have the funds and I like this suit.... Will make the 2lbs adjustment and will let you know how it turned out. My BC does have 40lbs lift, so won't have anyworries there. Thanks for your help. will be in touch.