Buoyancy

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sharkbitejeff

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Messages
37
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Location
Sycamore, IL
# of dives
25 - 49
I weigh 170 lbs. and I just bought a new 7 mil Bare wet suit with the 7 mil hooded jacket. normally I use a 7 mil with hood and gloves and 12lbs of weight . With the new set up last weekend in the quarry I had 22lbs and still could not descend. I had to pull my way down to the bottom using the bouy rope. Any suggestions??????
 
Yes.

Get a drysuit.

Yes, I'm serious. With that much neoprene you will ALWAYS be over-weighted at depth and under-weighted on the surface. Sadly, it's the way it is with a thick neoprene suit.

On the surface the suit is full of air, not crushed which gives you lots and LOTS of flotation. As you descend through what I call the "crush zone" at about 10 - 12 feet the suit will start to compress. As it compresses it is not as "floaty." As you move back up in the water, the suit will expand causing it to be more floaty. It's a never ending battle with the wetsuit. I wish this would be discussed more in OW and at the dive shop.

Also as your suit ages this will become less pronounced as the air cells in the neoprene break down. Also as the suit compresses it loses it's ability to keep you warm.

There will be "experts" who argue this saying " I don't have a problem " but I challenge you to dive with them and watch. It's simply a natural phenomenon and can't be avoided, only managed with much input from the diver.
 
Dry suits with insulated under garments are nice, as well as expensive, requiring more upkeep, a peevalve or Depends, and more weight. Back to your question...
I weigh 170 lbs. and I just bought a new 7 mil Bare wet suit with the 7 mil hooded jacket. normally I use a 7 mil with hood and gloves and 12lbs of weight . With the new set up last weekend in the quarry I had 22lbs and still could not descend. I had to pull my way down to the bottom using the bouy rope. Any suggestions??????
From 12 to 22 is a major jump, and I guess you're talking Freshwater? I wear 24# lead in FW with my 7 mil, but then I weaigh over 200# with too much adipose. :blush: I don't know what you mean by hooded jacket exactly, but what I hated to read is that you pulled yourself down the rope. You need to descend on your own so that you won't get in trouble ascending when your wetsuit becomes more buoyant as Randy described. Don't do that, ok?

If your previous 7 mil was old vs the new 7 mil Bare suit, the new one will be more buoyant - at least for a long while, depending on use and other treatment. The new Bare along may have needed more weight.

Bare sells 1 mil and 3 mil hooded vests in the US; I don't see a 7 mil hooded vest or jacket. Nope, not in the Canadian section either.

Anyway, with lead - it generally takes what it takes. As a new diver, you may well be holding onto some air in your lungs and there are techniques for dealing with that: Be sure you have your lungs empty, BC empty, and ankles crossed so you won't be fining. And make sure you have good control of your weight system, even if you need 24-26#. Add at least 4# for saltwater, maybe more with the vest/jacket.
 
I suggest a drysuit. Redundant bouyancy for all that weight, and it's warmer. I'll dive dry even in 80 degree water (although, very thin undergarments, if any).
 
Bare arctic combo ... its a 7 mm full thats sold with a 7mm shorty w/ integrated hood allowing for a lil' more versatility during your dive season...

I just ordered one myself 2 days ago (happy B-day to me!) ... this season I've been using about 15 lbs with a 7mm full (hood/gloves)... curious to find out how much I'm gonna need with 14mm of brand new neoprene on my core... , I dive steel tanks so that'll help a lil'...

here it tis... http://www.scubatoys.com/store/detail.asp?PRODUCT_ID=BareArcticSuit
 
If you are switching from an older 7mil to a brand new 7 mil with a 7 mil shorty/jacket then 10lbs, it is not much of a jump. New suits are a lot more buoyant, and there is the extra material.

Look for ways to get some of the weight on your back - weight pockets on the camband is an easy way to do it.
 
Bare arctic combo ... its a 7 mm full thats sold with a 7mm shorty w/ integrated hood allowing for a lil' more versatility during your dive season...

I just ordered one myself 2 days ago (happy B-day to me!) ... this season I've been using about 15 lbs with a 7mm full (hood/gloves)... curious to find out how much I'm gonna need with 14mm of brand new neoprene on my core... , I dive steel tanks so that'll help a lil'...

here it tis... BARE 7MM ARCTIC FULL SUIT COMBO reviews and discounts, Bare

I finally found it on Bare's site. Not under Layered Vests or even Colwater Wetsuits, but under the sub-categories. Not very user friendly.

That is a lot of suit on the torso. But for $275, a helluva lot cheaper than a dry suit for cold water and cold days. One way to estimate how much lead change is indicated is to stand in shallow end of pool with old 7 mil and add soft weights until it sinks; repeat with new combo suit; and the difference is evident for FW. Saltwater will require about 2-2.5% more overall weight. My BC will accommodate up to 30#, 20# of it ditchable, but I use 28-30# with my current 7 mil in Salt. I've I had one of those, I guess I'd have to add a belt with more weight or get another weight system.

Make sure all of that fits well before you pee in it, and get some Pet Urine Removal spray. :crafty:
 
Iam used to using a aluminum tank should I go to a steel tank first? or stay aluminum and purchase a weight belt?

You are under weighted and there are several ways to remedy this If you can swing it then by all means do for steel cylinders. In fact I bet swapping the AL80 for an X-80 will pretty much get you where you need to be You may even get to drop a little lead. More here.

From your belt question I assume the 22 pounds was all integrated. Going to a belt is not related to solving your problem, unless it was a small BC loaded to capacity. In any case you are better off with most of your weight not in the BC so get the belt.

Pete
 
I would love to have a dry suite, a new car, bigger house and a 401K that grows instead of shrinks. None of this is going to happen. I, along with untold of tens of thousands of divers learn to manage with a 7mil suit. Just like my minivan, they work, just not the best, but they get you there. As Pete said, get a good amount (at least 1/2) of the lead on a belt. Make sure you dump all the air from your BC and any trapped in your new suit if it is not a perfect fit. You may even have to go up a couple more pounds with a new suite until it gets crushed. Everyone is different, between myself and my 2 sons, we have a 30lbs spread in body weight, same gear and a 8lb spread in lead. It does not make sense, but that is reality.
 

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