Check Out Dive - Buoyancy Problems

[jeangadbois]

Last weekend was my first dive of my second year. The water was cold and ruff. The visability was from 5 to 8 feet, the worst I've ever bin in. Our plan was just to get wet get a little practice. We stayed near the dock and looked at the fish and garbage (found a bike). The dive went well but I had a hard time with my buoyancy. Last year I was doing alright with my bouyance I'm not proclaiming I was a master or anything but I thought I was doing well for the expearence i had.
What I'm wondering is, am I just rusty or is more difficult to time tune bouyance when you can't see much.

Jean

 

[the_dragon_no1]

Both. But mainly i think u are just rusty! Get in the water NOW ;-)



Sent from a Samsung Galaxy S2, @ Tapatalk forum app.

 

[Guba]

Has anything changed since last year? Gear configuration? Your weight? (Percentage of muscle, etc...) Your tidal volume (lung capacity/expansion)? Of course, it could just be experience and perception, but there could be physical changes that could be influencing your buoyancy. Start from scratch, do a proper weighting assessment in the water, and do what was suggested....gain experience by DIVING.

 

[spectrum]

It sounds like you were in a washing machine and surge raised havock.

 

[Panama Jones]

My first time in rougher low vis water I had trouble with buoyancy and it had nothing to do with equipment, weight or physical changes. Inability to relax. On the rough surface I was constantly moving to keep upright so had trouble descending. In the low vis water with currents, being tense affected my buoyancy. Wasn't till I just consciously relaxed did I get better.

Off topic... after those dives, I now know how it is possible for people in lifejackets to drown in rougher seas on the surface. It was a very long 10 minutes waiting for the boat to get to us while they picked up other divers.

 

[jbark]

You said you "stayed near the dock" that suggests to me that the water might have been fairly shallow?

I know that I have trouble when trying to dive in 5-15 foot depths it is hard for me to stay neutral due to my breathing. When I am a bit deeper it goes fine for me. I think the most important thing is to remember that we (you and I) are still beginners and that we should not expect every dive to go perfectly. To me it is more important to do our best to identify what might have been going on and to work on improvement. For example one thing I have figured out is that i need to add air to my BC in painfully small amounts and then wait a bit to see if I am OK before adding more or dumping. Small changes seem to be the ticket.

cheers,
Jerry

 

[TSandM]

You set yourself up for a difficult dive! When you have been out of the water for a long time, it's not a bad idea to do the first time back in a pool, or other very benign setting, just to remember how to breathe in a relaxed fashion, and practice with the BC. Stress does strange things to one's breathing, and breathing is the very core of precise buoyancy control.

Low visibility definitely makes things more difficult, because you don't have the visual references to notice variations in depth as quickly. It's not a bad idea, in those conditions, to dive fairly close to the bottom. If you are 12 inches off the sea floor and go up 12 inches, you are likely to notice this; if you are four feet up and go up a foot, you may not, but the same buoyancy adjustments need to be made.

Surge can definitely complicate buoyancy, especially if it is surge against a wall or reef, where the water has to go SOMEWHERE. When it can no longer go forward, it WILL go upward.

I would suggest perhaps choosing a somewhat smoother day or more protected site for your next outing.

 

[jeangadbois]

Thanks guys. I will defenatly do a weight check, I'm planing on getting wet again Monday.

And nothing had changed from the past summer.

 

[boulderjohn]

As jbark suggested, it sounds like you were shallow. I assume you were diving with heavy thermal protection, let's say at least a 7mm wet suit. In terms of buoyancy, there is nothing harder than diving in shallow water with a thick wet suit.

Let's say that you were diving in 17 feet of water, or about 1.5 atmospheres of pressure. With a thick wet suit, you need more lead to submerge than you need once you are down because of the compression of the suit. Let's say you had 2 liters of air in the BCD at 17 feet to be neutral. If you go to the surface, those 2 liters will now be 3 liters. The same thing will be happening to every bubble in the thick wet suit--they will all expand to 1.5 times their original size at depth. Every time you go up or down a couple of feet when diving at that depth, it makes a huge difference in buoyancy, and you have to adjust constantly.

Now let's say you go down to 99 feet and have that same 2 liters of air in the BCD. If you go up to 82 feet, the same amount of ascent, that 2 liters will only expand to 2.3 liters. The deeper you are, the easier it is to maintain your buoyancy.

If you want to do the math, the formula for change in volume is V₁P₁=V₂P₂. (The pressure has to be in atmospheres.)

 

[j yaeger]

same suit as last year...but a wee bit dryer after the winter!!!!!!!
warmer,but more bouyant cells!!!
i'd say soak it!!!!!with you in it !!!
problem solved...
have fun
yaeg