Question about drysuit weighting

[Aerobics111]

So I do surface weight check with 500 psi left in my tank, fully dump all the air in my BC and drysuit, fully inhale and can float at eye level. As far as I know, this is the proper way to do a weight check.

But when I actually dive, towards the end of it, I struggle to stay at 15ft unless I go vertical to squeeze all the air out of the drysuit. But this makes me feel un-secure so I've been adding two extra pounds to my weight to make myself feel more comfortable.

My question is: does the extra two pounds matter to buoyancy control at depth (say 100ft)? Is it common practice to be purposefully 2 lbs over weighted or we should still strive to trim to the minimum when drysuit diving?

 

[Alekseolsen]

Seems to be you should do the surface weight check without going vertical to dump all air first.

Guess you then end up with the two pounds extra

Buyoncy control at 100ft should be a breeze almost regardless of weight - its the shallows that may be challenging.

 

[tbone1004]

with a drysuit, gas=warmth, so there is no real hard and fast rule to how to weight yourself in the drysuit at the surface like we would with a wetsuit which has a fixed buoyancy characteristic at the surface. Trimming to the minimum is ideal with a wetsuit but all you are doing is losing "warmth" with the drysuit so put as much lead on there as you need to remain comfortable at the end of your dive.
Don't go hog wild, but if 2lbs makes you more comfortable then dive the 2lbs, if it needs 4 because you're finding yourself getting cold, then dive with 4. It's not permission to go crazy and put 20lbs on there just for kicks, but it's a very different paradigm than with wetsuits.

 

[rx7diver]

So I do surface weight check with 500 psi left in my tank, fully dump all the air in my BC and drysuit, fully inhale and can float at eye level. As far as I know, this is the proper way to do a weight check.

Hmmm. I don't do a drysuit weight check this way. What you're doing is sort of how I learned to do a wetsuit weight check.

For wetsuit diving, we were taught (for recreational diving) to have the cylinder completely full, have the suit completely flooded (i.e., no trapped air bubbles), and have the BC completely empty. Inhale, and float, hanging vertical, at eye level. This is for Midwest diving in a full two-piece 1/4" (6.5mm) wetsuit with hood and gloves, and a old-school steel 72 or an Al 80.

This approach would keep you at the surface when you are heaviest in the case of an emergency. Dropping your weight belt (assuming you are properly weighted) would get your mouth and nose above the water, too, and maybe keep them there as you exhaled and inhaled.

In reality, with experience, you would decrease the weight on your weight belt a bit (and use a competent surface dive for descending), because your wetsuit compresses with depth.

rx7diver

 

[Aerobics111]

Seems to be you should do the surface weight check without going vertical to dump all air first.

Guess you then end up with the two pounds extra

Buyoncy control at 100ft should be a breeze almost regardless of weight - its the shallows that may be challenging.

You are right. It's the shallows. I got it backward.

 

[Aerobics111]

with a drysuit, gas=warmth, so there is no real hard and fast rule to how to weight yourself in the drysuit at the surface like we would with a wetsuit which has a fixed buoyancy characteristic at the surface. Trimming to the minimum is ideal with a wetsuit but all you are doing is losing "warmth" with the drysuit so put as much lead on there as you need to remain comfortable at the end of your dive.
Don't go hog wild, but if 2lbs makes you more comfortable then dive the 2lbs, if it needs 4 because you're finding yourself getting cold, then dive with 4. It's not permission to go crazy and put 20lbs on there just for kicks, but it's a very different paradigm than with wetsuits.

Thanks for the great answer!

 

[Roy_W]

I am also in the learning stage of drysuiting and here at the moment the water is at 6°C ( 42°f). So extra air is very much welcome..

For the first few dives I added 1 extra kilo, 2Lbs, for exactly the same reason as you, difficulty remaining at the 5m-3m mark. This allowed me to have some extra air, therefore a little less cold.. I had a lot of problems with floaty feet.

I am now on my 12th dive with the drysuit and I can now remain at 3-5m without the extra weight..

Although it doesn't give me much margin for extra gas in the suit.. I have also subsequently learned how to change my trim as I ascend in order to ensure that the air leaves my feet throughout the ascent, small movements from horizontal to not quite horizontal and back again..

I think that initially, even 2kg (4lbs) is not so much, at least until you start getting your buoyancy perfected ; unless of course you are already overweighted. You will probably shed the extra weight as your drysuit skills/experience goes up. Although that also depends on your capacity to accept or refuse the cold ;-)

My wife who has much better buoyancy control than I do added 1 kilo initially but has now added another because she feels the cold too much.

Another important factor will also be the size of your wing, and just how deep you are diving. Also is the extra weight ditcheable ? If your dry suit flooded would your wing be capable of providing enough lift ?

 

[rjack321]

So I do surface weight check with 500 psi left in my tank, fully dump all the air in my BC and drysuit, fully inhale and can float at eye level. As far as I know, this is the proper way to do a weight check.

But when I actually dive, towards the end of it, I struggle to stay at 15ft unless I go vertical to squeeze all the air out of the drysuit. But this makes me feel un-secure so I've been adding two extra pounds to my weight to make myself feel more comfortable.

My question is: does the extra two pounds matter to buoyancy control at depth (say 100ft)? Is it common practice to be purposefully 2 lbs over weighted or we should still strive to trim to the minimum when drysuit diving?

Trying to do this on the surface is the bulk of the problem. That tends to migrate all the gas out of your legs and towards the dump valve so your insulation is smushed with 1.5-2m worth of water pressure and you'll be cold. Try laying on the bottom in 2m of water, wing empty, with a near empty tank (50bar) and your suit gas at a comfortable warm-ish inflation level. Having some of your lead in drysuit pockets helps or small lead bricks on the bottom (or buddy standing next to you with some 0.5 to 1kg bricks). Add or subtract lead until you're comfortable. You can move it from your head towards your feet or vice versa later, at this stage you are just trying to get the total amount or lead right.

 

[wetb4igetinthewater]

To follow up on what @tbone1004 said, I describe the process as having nearly empty cylinder(s), an empty wing/BCD, and a dry suit as empty as possible yet still maintaining warmth and comfort (don't dump all the gas out and be shrink wrapped as that isn't comfortable, and you will get colder faster). All of this at your safety stop, not the surface. When I teach open water, I do this check at the end of OW1 and repeat until their weight is dialed in. usually after OW1 it is.

Don't forget to do this horizontally and also distribute weight so that you effortlessly can remain in trim.

 

[grantmac]

I've been doing this vertical with the suit empty and 50bar, finding myself freezing especially at the end of the dive.
Weighting for a comfortable suit inflation seems a lot more comfortable.