fear of uncontrolled ascent

[Debbielou]

Hi there, and Happy Easter!

Once upon a time in the pool I found myself heading rapidly toward the surface when I had no plans to do this. I told my instructor that I already did the emergency ascent without being told to do it. We were to do that the next week. I was in the deep-end trying to do bouyancy control with my son, and the next thing I knew...there I went. It didn't feel very good on my ears I'll tell you. I went back down to do it again, and I just put 2 small bursts of air in the bc, and I started right back up again. My son grabbed my ankle to keep me from going back to the surface. I had to laugh, but in all honesty, it really made me think about that happening in the ocean and that wouldn't be a good thing. My pool sessions haven't been 100% for me as I had a hard time finding a bc that was the right size, and (if they brought the right size, someone else new ended-up with it). I need to have some time with a bc that fits before I know what will really happen, but I do think about this problem happening. My son or my husband can't watch me all the time to see that I don't go flying to the surface. I was only weighted with 3 lbs. and just that SMALL amount of air brought me up to the top. My son thought maybe I put to much air in, so when I did it the second and third time, he saw that there was hardly any air coming out of the bc when I let it out. My instructor told me that when my bouyancy was correct, when I exhale I would sink a little, and when I inhale I would rise a little....but I rose alot.

Any comments or suggestions?

Thanks, Debbielou

 

[Walter]

Debbielou,

Buoyancy in shallow depths (a pool) is tremendously more difficult than in normal dive depth (25'+). In a pool, I adjust my buoyancy in the shallow end, then as I move from shallow to deep and back I fine tune it by taking deeper breaths in deeper water and shallower breaths in shallower water. If you get your buoyancy worked out in a pool, the ocean will be a snap.

WWW™

 

[Heads Up]

I do an hours pool work every week and have found it tremendously useful with regards to maintaining neutral bouyancy when diving in the sea.

Don't bet put off - practice makes perfect

 

[herman]

Hi Debbielou,

I can't help but question your weighting. 3 lbs is a very small amount of weight especially for a new diver. A 3mm shortie takes almost that much weight by itself. Also, a standard Al-80 tank is about 4 lbs positive when empty so unless you (your body)is at least 1 lb negative to start with you are going to be positive at the end of a tank like it or not and this does not take into account any additional bouyancy from any wet suit, air in the BC or natural body bouyancy. Body composition does make a big difference in how much weight people need but most people are naturally somewhat positive and women tend to be more so. I suggest you do another (with another DM if possible??)weight check and there is always purposely overweighting a little until you get it under control.

 

[cherinere]

I agree with Herman, I consider myself a small woman and I use 6 pound at the very least and still feel adding another 2lbs would help. Not that you should stop practicing if you go with more weight but I think you would find a happy medium by adding more, unless of course your son enjoys holding you under the water. I know mine would love to sometimes. Good luck and let us know if you try the extra weight and if it makes a differents. Cher

 

[The Chairman]

Hey All,

ScubaPro did research on this very subject not too long ago. Their conclusion was that under thirty feet there was a chance to get a runaway ascent under control. Above that there was little chance to NOT break the surface. It just happens too fast. Make sure that you adjust your bouancy with an ALMOST EMPTY TANK (300-400psi). If you are merely nuetral at the beginning of a dive, then you will be positively bouyant (but not happy) when you are into your dive. While the compression of you & your wet suit will accomodate for this at depth, in the shallows you will become a rocket. While a mere two pounds overweight should NOT make much difference, it is not something I have had any of the students I have helped try. Try to find that nuetral bouyancy, like your life depended on it... 'cause it does! The big thing on the first pool dive, is adding weights thru the class and then making sure everyone gets a good handle on what they will need at the end of the class. BTW, remember you will need even more when you hit salt water.

Pete from Orlando...

 

[Iguana Don]

Debbielou,

When adding air to your BC, add it in very small bursts one at a time and wait for the change before adding any more, adding short bursts takes a little time for the change to take affect. Hope this helps.

ID

 

[The Chairman]

Hey Debbielou & All,

What I meant when I said to adjust your bouyancy with an almost empty tank... refered to the practice of determining the amount of weight you need to be neutrally bouyant. Adjust your WEIGHTING with an almost empty tank (300-400 psi).This will make you a little negative as you start your dive, progressing through to neutral or almost neutral as you empty your tank. Yes, air does have mass and therefore weight.

Pete from Orlando...

 

[WetDane]

Hmm, I would like to add something - I picked up on the fact that you never seem to get a BC that actually fit you - I think you should make and effort to go to the shop and see if you can pick one up early that will fit you, that way you are sure to have it. I think this is important because a bad fit will not allow you to relax the way a good fit wiil, if you get that thing on and it fits, you will be able to concentrate on the task and not on avoiding slipping out of the BC...

Also, I suggest you go to the BC list as there was recently a thread on BC's or women and you may be able to get good data from that.

Cheers,
Terkel

 

[caymancase]

To achieve neutral bouyancy I have been taught that, with proper weighting (not overweighted), proper equipment and proper breathing technique that you need not put any air in your BC underwater and only use an inflated BC for positive bouyancy while on the surface. This is the way that our instructor teaches and people seem to have alot more control over their body positioning in the water..streamlined without their upper body floating above their heads so that their "walking" through the water and not a lot of hand movements. They also use alot less air and enjoy themselves more without fiddling with their BC during their dive doing constant adjustments. Putting air in... letting air out... Just my .02. Casey