Cold water weighting

[Oper8ter]

I'm sure this has been asked before but, I have a question regarding weighting. My wife and I dive in Ohio, with mostly colder water, we dive using 7mil farmer john/shorties(still trying to talk her into dry suits). I only need 16 lbs and I can descend easily, but she needs a lot more weight, then on the bottom she feels severely over-weighted. I'm suspecting it's maybe a little inexperience and it seems to be less and less of problem, but I figured with as much experience and knowledge there is here, maybe someone knows of a way( aside form pulling her down by her fins to make this situation easier. I know as we get down a little bit those thick suits compress and lower the buoyancy a little.

 

[SteveAD]

Many divers (especially newbies) will unconciously kick or scull with their hands while trying to descend.

My first direction when doing a weight check is "cross your ankles and clasp your hands together"

It is also common to fail to completely empty the BC--get vertical possibly even slightly leaned back hold the hose up over your head press the oral inflate/deflate and give it plenty of time to vent.

Thick wetsuits do have a lot of bouyancy change with depth, that is the reason we wear bcs.

Best time to do a good bouyancy check is at the end of a dive, with a near empty tank and a diver who is relaxed and in the groove. You can either (1)take whatever weight was used for the dive and start removing it in small increments until she can no longer get/stay down, or (2)remove a significant part of what was used for the dive and then add small increments until she can get/stay down.

I find option 1 often works best.

 

[Colliam7]

I only need 16 lbs and I can descend easily, but she needs a lot more weight, then on the bottom she feels severely over-weighted.

Good advice from Stevead on the descent technique. A couple of questions and a comment. What is 'a lot more' weight for her (20,24, more)? Are you using the same BCDs or is hers more positively bouyant? The comment is that, in addition to the issue of finning / sculling during the descent (which is not uncommon among newer divers, and may reflect a level of anxiety), does she breath deeper / more rapidly when entering the water, possibly because of the colder water (I certainly do) but possibly because of initial anxiety? Your description of her feeling overwerighted at the bottom suggests that, once she is down and more comfortable (as comfortable as one can be in cold water with 7mm of neoprene, I guess) her breathing is more under control and she is less positive than at the surface.

 

[Ber Rabbit]

Come on out to Meet-n-Greet at Gilboa April 26-27 and we can see if we can find the problem. I'm willing to bet Stevead and Colliam are on the money and it will be a simple fix.
Ber :lilbunny:

 

[Buoyant1]

Many divers (especially newbies) will unconciously kick or scull with their hands while trying to descend.

My first direction when doing a weight check is "cross your ankles and clasp your hands together"

It is also common to fail to completely empty the BC--get vertical possibly even slightly leaned back hold the hose up over your head press the oral inflate/deflate and give it plenty of time to vent.

Thick wetsuits do have a lot of bouyancy change with depth, that is the reason we wear bcs.

Best time to do a good bouyancy check is at the end of a dive, with a near empty tank and a diver who is relaxed and in the groove. You can either (1)take whatever weight was used for the dive and start removing it in small increments until she can no longer get/stay down, or (2)remove a significant part of what was used for the dive and then add small increments until she can get/stay down.

I find option 1 often works best.

I had the same issue, and crossing my ankles worked ! Moving your legs is working against yourself believe it or not!

 

[don Francisco]

It isn't reasonable to compare your weight requirements to your wife's. Many things are at play, but in the end there may still be differences.

Starting with the easiest, happy feet (finning) can be cured by pure mind control or by crossing her ankles.

Emptying the BC can be practiced, be sure the open valve is fully at the top, so there aren't any trapped air pockets.

Burping the wet suit, while no fun in cold water, is especially important for women since their shape makes it more likely that air gets traped between the suit & the skin. You don't get as much chill if you burp while the neck seal is still out of the water.

Lung air retention is trickier, and subject to the catch 22 of diving; people who have problems descending know it, than makes them more anxious, so they hold more air, which makes it even worse. This will go away over time. Best bet; dive slightly overweighted, and as you gain confidence wean off the extra pounds one at a time.

Technique for easier descent, just before descending take a big breath & fin up hard for a second, lifting up out of the water slightly, empty BC & exhale on the drop, using the extra momentum to carry you down 3 or more feet before inhaling. Shallow breaths only for the next few feet to avoid popping back up.

When all is said & done, there will still be large weight differences among divers because of physiologal differences. Fat has a specific gravity of .9 or so, so every 10#s of body fat requires 1# of offsetting lead, Muscle is slightly denser than water & tends to sink, as does bone. For that reason a 225# tight end would need far less weight than a 225# overweight couch potato.

Women tend to have higher fat ratios then men & thus tend to need extra lead. You can somewhat predict the "body lead" needed by looking at high high someone floats in a pool, some float with their heads above the surface, some head & shoulders, & others, like myself sink & can walk across the bottom with no problem.

In the end, don't compare your wife's lead needs to yours, just try to help her optimize her weight for her needs.

Final note, experience speaking here, it'll go a lot easier on everybody if you get an outsider, or a professional to help. Teaching folks close to you doesn't always go as smoothly as one might hope.

 

[Anti-Hero]

Great posts, I've noticed recently that I was able to eliminate almost 6 lbs. from my normal load on the last dive. I'm sure it has to do with comfort levels increasing, but I never thought about crossing my ankles. I want to go diving right now and try it. Perhaps I can ditch another 2-4 lbs.

 

[Oper8ter]

Thanks for all the words of wisdom. I know my weight has nothing to do with what her weight should be, I just threw that out there. She uses upwards of around 40#s. I will definitely be have her try the crossed fingers/legs thing. I'm thinking it might have something to do with her BC as well. She has a Dacor Falcon, and I think I remember seeing a plastic type of back plate.
I can't make it to the Meet & Greet in April Ber, but do plan on diving Gilboa this year. Maybe we'll be in the same place at the same time one of these weekends in the summer and we can hook up.

 

[Ber Rabbit]

Yowza! That's a lot of lead, no wonder she feels severely overweighted at depth. I should be at White Star May 10, Portage May 17 and White Star again May 18 with my advanced class then Gilboa June 28-29 with OW students. You're more than welcome to come to any of those dates and I'll help you.
Ber :lilbunny: