I can't sink!

[salmon_ella]

So my last thread blew up a little.... >.> but new question, new topic!

I'm very naturally buoyant. You know those games you play as kids where you try to see who can sit on the bottom of the pool longest? Yeah, I can't do that. I float right back up even on a full exhale.

On my OW dives I was wearing a 7mm Farmer John wetsuit and 7mm oversuit, plus hood and gloves. My instructor stated as a rule of thumb we should be wearing 10% of our body weight plus 15 pounds. I weigh roughly 110 pounds so was wearing 26 pounds of weight. On a couple of the dives I went down holding arms with my buddy and it went fine. When I tried by myself, I dumped all the air from my BC (I'm pretty sure) and exhaled as far as I could, went down about a foot, and floated right back up. The instructor had to come back up and get me. Totally embarrassing. *facepalm* My certified friend suggested "dolphin diving" headfirst from the surface but I have heard that isn't the ideal way to do it.

Do I need more weight due to my natural buoyancy? Or am I doing something wrong?

 

[northernone]

We all need different amounts of lead. The 10% guideline only has worked on maybe 5% of the divers I know.

Sounds like you need a little more. It should not be a struggle to get down. Just add a couple more lbs.

 

[salmon_ella]

We all need different amounts of lead. The 10% guideline only has worked on maybe 5% of the divers I know.

Sounds like you need a little more. It should not be a struggle to get down. Just add a couple more lbs.

Another question then. My BC only has 30 pounds of lift. Do I need to worry about getting up toward that limit?

 

[aquacat8]

110 lbs is not much to personally weigh, I’m betting that farmer John is really buoyant... 14 mil on your core is a lot, and girls don’t usually need to double up in the thigh area, we usually have some natural insulation there. If you can try a 7mm full wetsuit with an integrated hood and 5 mil vest (if needed) or hooded vest.

Maybe your BC is really floaty too. Steel tanks, a steel backplate and wing, there are ways to drop lead...

 

[KatieMac]

I jump in the pool at my sister's house. My brother-in-law can sit on the bottom by just exhaling. I need 2 lbs just to get off the surface. So yes, everybody is different and women are different than men - no comparison. And I agree with northernone, 10% doesn't work for me - 120 lbs, 3mm wetsuit and I dive with 10 lbs, although it's a bit more than I really need - I can get by with 8lbs.

And if you can't get down and stay down without help, you need more weight.

 

[RyanT]

A couple of things. First, you were wearing A LOT of suit and that is definitely going to cause you to be quite buoyant. In fact, if understand correctly, you had two 7 mm pieces (the farmer john), plus another 7mm suit on top and a hood and gloves? If so, I'm surprised that you could even get down with 26 lbs.

Second (I'm speculating a little more here), when you talk about your "natural buoyancy" you might be surprised to learn that you are not exhaling as fully as you think. For a while my buddy was having a similar problem and claimed she was exhaling. As it turned out, when she got a little nervous, she was actually only exhaling a little and her "empty" lungs were still providing a bit of flotation. Learning to relax can help a lot, some of it of course, just comes with experience.

 

[RyanT]

Whoops, I just re-read your post and realized you were talking about the oversuit as part of your farmer john system...it's still a lot of rubber to be wearing.

 

[aquacat8]

Sometimes new divers are also kicking up without realizing it

 

[broncobowsher]

You have just about everything possible working against you. Naturally buoyant, 7mm, in a farmer john, and I am going to guess an Aluminum 80 as well. You have everything shy of wearing a life jacket trying to keep you on the surface. The fact you can almost get under says you are really close. You need to compensate for the air that will be used as well. Add 4 pounds and see what that does.

Don't worry about only having 30 pounds of lift. Unless you are taking the wetsuit off while under water and keeping all the weight on you, there will be lots of lift available. For those nit picking, yes the wetsuit will compress, but not to nothing. And for someone just starting to dive you won't be going deep enough for it to be a problem.

 

[wnissen]

My (inexperienced) instinct is that you only need enough lift to overcome the net negative buoyancy at your heaviest time. That's when you have 4.8 lbs. of air in your tank, at the beginning of the dive. Are you doing a weight check with a full breath of air at the surface?