Dry suit weighting

[JoelW]

I have found that I work out the weighting a little differently than others. I don't worry about the tank initially. When I have gone to different layers underneath the suit I set up everything and the leave the tank and reg off. I then get into the water, make sure that the suit is purged and determine the amount of weight necessary to sink. After that I need to account for the tank and reg. An Al80 is +4 empty and -2 full. Add a reg and it works out to about +3 empty and -3 full. To make sure that I can sink with an Al80 I add to 3 more pounds to make up for the +3 that the AL80 is empty. Now I know that I can sink with an empy tank and will be slightly negative with 500 in the tank. For other tanks I work out the variation from an Al80. For example, the tanks that I normally use are LP95s. I know that they are 6# more negative than the Al80s. So I take 6# off for steels. It has worked so far. Of course, I am counting on the data for the tanks being accurate. But, even if it is slighly off I can add a pound or two as insurance.

One thing about heavier weighting is what has been said before, placement of the weight makes a big difference. Steels are nice because they lay the weight along your spine and make trim easier to hold.

JoelW

[davisj]

Beeger, and others, Thanks for your replies to my post.

I have the Balance BC with the velcro weight pockets. I have stuffed this BC to the limit, and the weight is at 30 lbs. I have to admit that having 10 lbs in each pocket makes the BC very uncomfortable around the hips. With a neoprene wet suit, some cushioning is provided, but I don't know how the fit will be with the TLS. Velco is not a good idea in my opinion. I have been with divers that lose weight, which terminated the diving for the day. I really like the idea of weight integration, but I will end up movong some weight to a belt.

Jeff

[freedivernd]

Jeff,
maybe a dumb question, but I'm not much of a diver. When you move weight to a belt with a dry suit do you wear that belt on the outside or on the inside? The reason I ask is because when I first read your post I thought for compression issues you would like a rubber weight belt like I use for freediving.. meaning it never needs adjusting like a cloth/nylon belt but then I thought if you wore a rubber belt like I do you would never get air to the other side of it unless you had two inflation lines for your suit. Or maybe do you just hang the belt and weights from a d-ring Doesn't a belt restrict air movement in a drysuit?
Curious Fred

[DRE]

A belt doesn't interfere with gas movement in the suit. Usually what you need to do though, is to tighten the belt when arriving at depth.
You always need to have some kind os ditchable weight option, whether it is a canister light, a weightbelt or integrated weight option. Having all of the weight ditchable isn't the best idea, however. You need to figure out how much weight you will need to ditch at depth to be able to regain neutral boyancy at depth. Making yourself too positive will lead to an uncontrolled ascent to the surface, which should be avoided at all times (for obvious reasons). Also, if you're wearing a drysuit, you do have backup boyancy right there, so the amount of ditchable weight can be greatly reduced.

[davisj]

freediverND,

As DRE said, the belt won't restrict the movement of air in the suit. The belt is on the outside, case you have to ditch it.

DRE,

I still like the idea of integrated weights. I have a capacity of 30lbs, which I think will be about right. I'd be able to add a bit of non-ditchable weight somewhere. The question would then be, if wearing a dry suit, BC and aluminum tank, and you were weighted properly to begin with, wouldn't ditching 10lbs from one weight pocket be too much ?? Would that make one underweighted, and in danger of a rapid ascent ??

[DRE]

Depends - usually being able to ditch a couple of pounds should be enough, but it varies from person to person and also how comfortable you feel as a diver.
Weighting is one of the most overlooked parts of a diver's education and takes lots of practicing and experimenting.

[beeger]

jdavis - how much you need to have ditchable really depends on what your buoyancy shift is going to be, taking both the tank and suit shifts into account (see my earlier post). Having too much or too little ditchable is a dangerous idea. You may want to look to move some of that pocket weight to the tank. This can be done either by using a heavier tank (steel) or by adding weight to the tank some other way. There are a number of products out there that will allow you to strap or attach weights to the tank in one way or another. Perhaps exploring one of those options would help. From what you have said, having 20 lbs ditchable is too much for 30 lbs total weight when you consider the fact that you will be in a shell suit.

There's nothing magic about proper weighting. But as DRE said, it is often overlooked.

[jmsdiver]

Everyone here has had great replies and we have probably beat this thing into the rug, but I'll give my 2 cents worth.

When I figured out my weighting for my Viking, I went about it like any thermal protection: took 10% of my weight and added approximately 3 pounds and hopped in the water with the rest of the kit, deflated the dry and BC, normal breath, and attempted to float just below the surface, exhaling should allow me to sink. If not, then I added some weight. I currently use about 22 pounds with just an AL80. The weight changes with different configurations and objectives.

Cheers

[davisj]

Thanks to all for the replies.

Correct me if I'm wrong. The weight that is used for diving a drysuit is:.. 1) Compensate for the volume/buoyancy of the drysuit and thermal insulation, and 2) the buoyancy of an empty tank.

If one loses all the buoyancy of the suit (suit completely flooded), AND the BC fails to inflate, the amount of ditchable weight required would significant !

How does one plan for such a senario ??

Jeff

[beeger]

The worst case scenario is that you have a BC and drysuit failure at the beginning of the dive (when your tanks are heaviest) and at max depth (when your exposure suit has compressed the most). Dropping the ditchable weight will reestablish your neutral buoyancy. It is the *shift* in buoyancy during the dive that you need to be worried about when it comes to ditchable weight.

jdavis - let me know if I'm not answering your question. Weighting is important so I want to make sure you feel like you are getting the information you need, if not from me then from someone else.

The single most important thing, however, is to make sure you are carrying the minimum amount of weight needed. This will obviously vary by person, exposure protection, etc.. But pay careful attention to the weight you are carrying. The beginning of the dive tends to be the toughest for the average diver. When you begin your descent concentrate on a slow, full exhale. Also, just as a test, try crossing you ankles. This will prevent any kicking that sometimes happened without people knowing it ... this is especially true with new divers. People get nervous on the surface, start breathing rapidly, and start treading water with their fins. Then, when they are not able to get down, they slap on more weight, or get more weight slapped on them by some instructor/dive master who is more concerned with getting all the students underwater and getting the dive going. Even comfortable divers will sometimes subconsciously tread water with their fins. This is yet another reason why starting an immediate horizontal descent is a good idea - it makes you much more aware of your body position and activity.