Why neutral buoyancy isn't

[Doug Allen]

Well said Warren....I was told by my CCR Instructor that I'd not need any weight at all...turns out I need 18 lbs....in a drysuit...15 lbs in a 5 mil wetsuit....as for breathing with CCR....I never noticed any change with the Optima by Dive Rite. But, the diluent flush b4 ascent will screw with buoyancy, especially with a dry suit....thus the drysuit squeez......fear of over-inflation and the need to dump excess air with a deco commitment at 20' is something I'll have to learn to deal with...but, an under-inflated drysuit will result in wet underwear if diving with a "Pee" valve that is not hooked up....dive and learn.

 

[cowdog77]

"The more air you have in your BC, the more susceptible you are to changes in buoyancy from slight changes in depth, so the more you have to add/vent to control your buoyancy."
When I figured that out, I was able to drop 4 lbs and any concerns about unplanned ascents. That bubble can make a big difference real quick.~

 

[jefffalcone]

.......

 

[RJP]

I just don't think that buoyancy or proper weighting is a problem for me. Maybe it is for others. I seem to have gotten it at the start.

I have dove (dived, diven) with as much as 8 pounds too much weight when I was using an AL100 a couple of months ago and didn't notice the difference while getting along under water. Maybe it's because I didn't pay attention. I just want to be sure that when I come up to the 5 meter stop that I can do it without struggling to stay down. Extra weight is my friend.

It's impossible for you to be diving with 8lbs TOO MUCH and not notice the difference, unless your bouyancy control is SO horrible that you're all over the place on every single dive anyway.

If that's the case, then it's possible. that you wouldn't notice extra weight. However that is completley incompatible with your first statement that bouyancy and weighting isn't a problem for you, and you clearly haven't "gotten it" from the start.

If you had good bouyancy control and weighting you would notice ONE pound too much. Sounds to me like you've simply gotten used to being improperly weighted. That DOESN'T mean that you "get it" at all.

 

[JCAT]

If it can help someone to understand better and to ultimately control their buoyancy better, then I'm a happy camper

Rick

It did! Please continue!!

 

[Bob]

Rick,
Excellent article. Well written and to the point. almtree: Bob

 

[tonka97]

Personally, I can't see where buoyancy is such a big deal. You figure about 10% of your actual weight, give or take a few pounds, depending on your muscular content and how thick a wetsuit you are wearing, if you are using one. If you sink after letting the air out of your BCD you should be OK. When you get to the level you want to stay at, pump enough in your BCD to stay at that level. What's so complicated about that?

OK, I weigh 150 lbs; just got back from Bonaire; by your calculations I would have been 7 lbs overweighted.

My optimal need was only 8 lbs; this enabled an easy safety stop with 500 psi. That 7 extra pounds, by your calculation, would have required a huge air bubble in my BC that would have wreaked havoc with my buoyancy control! Overweighting is probably the most glaring error with divers. My PADI AOW instructor, Ed Skaggs here in WV, started the course with dumping my excess lead! What a difference! I went from an average diver to a good one, with just this change!

Another error in your advice: When a diver initially enters the water, his suit has quite a bit of air contained in various spaces and objects (under and in inner lining of wetsuit for example), and this air will be dispelled as the diver descends.

New divers will often have difficulty fully exhaling to descend and control buoyancy due to tenseness. They will also tend to keep finning for the same reason, thereby preventing neutral buoyancy maintenance. New divers will also tend to use a variation of 'bicycle finning'. This will propel the diver toward the surface, therefore fooling the diver that "I need more lead to hold me down".

Most divers using your recommendations will be overweighted, and therefore will have difficulty with buoyancy, and will be working way too hard with their gear in and out of the water.

 

[Sideband]

Guys, give up on Garrobo. In another thread he said,

leejnd: I really don't care about becoming a more self-reliant diver. All I am interested in doing is getting wet and enjoying a dive now and then. As far as my buddy becoming distressed and in trouble, I'll help him/her out as much as I can without endangering my own life. Other than that, if things get out of hand, I know exactly how to send up a sausage, go to the suface and then look for the boat/blow a whistle for help, etc.

He's a good enough for him diver and doesn't want to improve.

 

[DivingsInMyBlood]

thanks rick, this was helpful.

 

[SNorman]

That's what every new diver should read or be told.