bouancy

[scubaboy14]

I found when I was diving on New Providence Island, Bahamasthat i floated to the top when I was on Barracuda Shoals on the reef which was at 10 feet of water. I am wondering if there is some techinique in keeping myself down in shawllow wateror is it just practice.

 

[Don Burke]

I found when I was diving on New Providence Island, Bahamasthat i floated to the top when I was on Barracuda Shoals on the reef which was at 10 feet of water. I am wondering if there is some techinique in keeping myself down in shawllow wateror is it just practice.

Try making sure you are exhaling enough.

You might want to add a couple of pounds for now and recheck your weighting after you have some more dives. It is normal for your weight needs to drop and you may be just a little ahead of yourself.

 

[LiteHedded]

I'm pretty new myself but on one of my dives I had a similar issue
all the air wasn't getting released from my bc because I wasn't holding the release hose thingie high enough due to a velcro strap on the shoulder
maybe you aren't getting all the air out of your bc and what's left is expanding as you reach shallower water?

 

[del_mo]

I'm pretty new myself but on one of my dives I had a similar issue
all the air wasn't getting released from my bc because I wasn't holding the release hose thingie high enough due to a velcro strap on the shoulder
maybe you aren't getting all the air out of your bc and what's left is expanding as you reach shallower water?

Remember, you can pull your release hose thingie to release the air. Then you don't have to worry about how high you hold your thingie.

 

[jcm996]

I personally almost never use the inflator hose to release my bc air. I usually use the pull cord on my right side letting air out of my shoulder valve. If i am having problems I put my head down and use the release on my lower valve and sometimes find a bubble trapped there.

But don't the newer BC now allow you to just pull the inflator hose down and release through the shoulder instead of having to hold it up?

 

[toodive4]

In Open Water Class you should have learned about a phenomena called surge. Surge is generally encountered in shallow coastal waters such as shoals. Surge occurs when wave energy comes in contact with the ocean bottom. Generally speaking an upsurging as is typically encountered in ocean dives with less than 30 feet to the bottom, divers will have a much harder time descending. In these conditions it is sometimes neccesary to overweight yourself. Another option is to use a down line and pull yourself down the line. My preference is a combination of both of these.

From personal experience I can tell this story. While diving on the Fenwick Shoals (off the coast of Delaware,) I encountered a strong surge condition. I had on my usual amount of weight but could not for the life of me get down. I decided to go down the anchor line and successfully reached the bottom at 35 feet. While at 35 feet I was fine and able to maintain my bouyancy. While swimming along I came upon some large rocks and decided to swim over them (this took me up only about 5-7 feet) to a depth of about 27 feet. At this point I felt like a vacuum cleaner had gotten hold of me and it was sucking me up to the surface. It was the surge. In general - once a strong surge gets a hold of you - you're just along for the ride. Once at the surface I was again unable to descend and aborted the dive. I should have put on more weight at the start.

While I have never dove the area you mention, I wouldn't be surprised if surge were part of the problem there. Try overweighting yourself by about 4 lbs and that should do the trick. If anyone else out there knows surge is not an issue for this site, please speak up...

Ken

I found when I was diving on New Providence Island, Bahamasthat i floated to the top when I was on Barracuda Shoals on the reef which was at 10 feet of water. I am wondering if there is some techinique in keeping myself down in shawllow wateror is it just practice.

 

[TSandM]

Scubaboy, you and I have about the same amount of experience, and the same problems.

First off, it is most difficult to maintain your depth within the first 30 feet, because of the proportionally large changes of pressure that occur there. Second, if you are anything like me, you're still too green to be able to sense when you have become positively buoyant BEFORE you are losing depth and worsening the problem. I have talked to a bunch of people about how to do this -- with drysuits, you can sense when the suit is "letting go" of you. My husband swears he senses it by his ears, although that doesn't work for me because my ears equalize effortlessly going up and I'm unaware of it. My instructor says that in water that shallow, I should be watching my computer, which definitely helps.

But the key seems to be venting "early and often" -- staying ahead of the need to vent and getting it done before you become positive. Somebody on this board posted an interesting approach to this with a BC, which I have yet to try, which is to depress the valve on the inflator and move the hose until bubbles begin to come out of it. Keep the inflator at exactly that position, and keep the stream of bubbles the same volume and velocity. Then you should be in a position to level off whenever you want.

Anyway, I don't know if any of that information is useful, but maybe it helps to know that other new divers have the exactly same problems!

 

[scubafool]

I found when I was diving on New Providence Island, Bahamasthat i floated to the top when I was on Barracuda Shoals on the reef which was at 10 feet of water. I am wondering if there is some techinique in keeping myself down in shawllow wateror is it just practice.

Maybe you are underweighted.

Maybe you are overweighted.

Maybe you need more practice with bouyancy control. BTW, this can go a long way towards fixing being overweighted.

Maybe you are not getting all of the air out of your BC.

If you are underweighted, the positive bouyancy of your wetsuit, the positive bouyancy that an aluminum tank has as it is breathed to lower pressures, any positive bouyancy that your body has, etc, etc. has to be offset by negative bouyancy (weights). If it is not, you will tend to float up. This will be worse as your tank gets closer to empty.

If you are overweighted, you have to carry more air in your BC. The more air that is in your BC, the more it expands if you start to go up, so the faster you will go up, the more the air will expand..... voila! you are at the surface.

My steel double tanks make me way overweighted. However, with a lot of concentration, I can hold a shallow depth with full tanks. That is only because I have practiced bouyancy control a lot. A newer diver at shallower depths will have trouble with this.

Make sure that you are getting all of the air out of your BC, like other have said.

 

[m3830431]

I found when I was diving on New Providence Island, Bahamasthat i floated to the top when I was on Barracuda Shoals on the reef which was at 10 feet of water. I am wondering if there is some techinique in keeping myself down in shawllow wateror is it just practice.

If this happened at the begining of the dive with an empty BCD you are most likely underweight. If it happened at the end of the dive it could be anything overweight, underweight, poor bouyance control and/or surge.