Too much Weight

[donacheson]

I've read a couple comments concerning weighting and "ego." I have to admit my wife did make a comment about how it all seemed to be a competition between the male divers. We had a number of lady divers in our group and that night I asked some of them and to a person, they all said the same thing. They asked me why, if you have no problems getting down and up are we (men) so obsessed about dropping weight. Let's be honest guys, could it be a little, just a little...about competition?

No, it's not about competition. Being underweighted can be exhausting, carrying a few more pounds of lead than that minimally required to remain neutral throughout a dive isn't a bad thing. However, increasingly excess lead weight makes remaining neutral increasingly difficult and it's serves no useful purpose.

 

[Scubakevdm]

Just a couple of thoughts, I'm killing about 20 minutes waiting for laundry.
1) Being properly weighted is not the same thing as being neutrally buoyant. You can be neutral even if you are grossly overweighted as long as your BCD has enough lift to counter the weight. You can also be neutral if you are underweighted, and while I don't find this exhausting, I do find it very uncomfortable, which I will explain in a minute.

2) Proper weighting allows the diver to:

Minimize drag by not pushing an unnecessarily large bubble through the water. In the event that the diver is propelling them self by swimming, this reduction also reduces effort, exertion, and therefore air consumption.

Be more stable in the water because a giant bubble isn't migrating all over their back, one minute at their neck, the next on their butt.

Most importantly in my opinion, it allows the diver to control their buoyancy with their lungs. The greater the volume of a bubble of air in your bcd, the greater the effect of depth changes on your buoyancy. If the volume of the bubble is great enough, even a slight change in depth will cause a change in buoyancy beyond the capacity of your lungs to control. At this point you either have to deal with it by adding or removing air from your BCD. This makes diving complicated, difficult and downright unnatural. Sometimes, like when you dive double 121's with a meaty fill, you have about a 22 lb swing to deal with between the full and empty-ish tanks, and there's just no way to avoid it, and a 22 lb bubble is a pretty big bubble.

Even if you're properly weighted, significant changes in depth will require some operation of your bcd, but the goal of proper weighting is to minimize this.

If you take too much weight off, and you are trying to dive using your lungs to control your buoyancy, you will find that you have to keep them pretty empty, which is an uncomfortable, very dissatisfying way of breathing. I personally breath alot more when I find myself in this situation, and feel that, while being overweighted may complicate diving, being underweighted uses alot more air.

I'm off to wash some clothes.

 

[jviehe]

You're NOT perfectly neutral at the surface - you're floating.

My gripe with the "PADI weight check" is that's all that's taught. It appears that proper weighting isn't, yet being neutral throughout a dive can make scuba such a pleasure.

Wouldnt the fact that if you breath out you sink, and if you breath in you rise indicate you ARE neutral? That is all we teach because it works for OW students. This stuff has been proven with hundreds of thousands of students.

 

[donacheson]

Wouldnt the fact that if you breath out you sink, and if you breath in you rise indicate you ARE neutral? That is all we teach because it works for OW students. This stuff has been proven with hundreds of thousands of students.

With a near-empty tank and empty BC on the surface, yes, you're pretty close. Doing that with a full tank isn't. Floating with the surface at eye level doesn't do it unless the diver's lungs are full - with a near-empty tank and empty BC.

Obviously, from the amount of discussion and confusion and misunderstanding about buoyancy on this forum it's not being taught properly.

 

[Piccola]

Dave C.
I always appreciate the advice of those who are certainly more experienced than I. That is how we learn. So Thanks...

You are correct in this appears confusing when I read it back...if I have trouble sinking, why would I have trouble remaining afloat with an empty tank? Quick answer is...I don't know. Could be several reasons. First remember I may not be detailling in such a way the those thinking of it scientifically can explain. Again, I am new and my perception of things may not have the exacting specifications to be explained scientifically. I have shed some lead since that dive so maybe I was just a little negative even with an empty tank, enough to make me feel like I was sinking. There could be pockets of air in my suit that gets evacuated during the dive. Would that account for at least some surface buoyance at the beginning of the dive. Maybe there is some air in my BCD at the beginning when I thought it was empty. I am now learning, just how to move around an get all the air out. What ever it is that I am doing seems to be improving my diving experiences. I have been going out every weekend and I seem to be 'working out the bugs'. I suspect as time goes on and I keep picking up tips from you folks, this will all work out.