Came up too fast

[stormchaser]

I am a newbie. About a dozen dives and an air hog. I was in Cozumel with a 100 tank. I swear that tank got buoyant as air ran out. We started out at about 80 feet and ascended up the reef to about 40 feet. I am wearing 22 pounds of weight. When I hit about 30 feet I shot right past the safety stop tried to swim back down but nothing doing. I tried every air release valve I had on the BCD. (one on each shoulder and one on the bottom back.

One problem could be, is that I was over weighted and still had a little air trapped inside the BCD?

This scared the hell out of me. Any suggestions?

 

[firstdive2005]

Hi Bud! Getting a rush like that is scary. Lots of things to consider from what you stated.
-Saying you had 22lbs of lead on you sort of means nothing until other info is added. For instance was your wetsuit new, full or shorty. Your own weight, are you slim or at a place where you may want to lose weight.(not sure how to ask that).
-When you state you hit 30fsw are you saying you where done the dive and ascending to your safety stop? or where you still multi-leveling your dive as usually done at Coz?
-I once watched a new diver trying to release air at the inflator hose and was actually inflating thinking he was letting air out. Did you maybe do this? Just asking as one generally doesnt blast that fast up if you have actually let air out.
-As a concern for your fast ascent I hope you where trying to blow air from your lungs as you ascended as to not embolize.
-One good thing for you is you likely where still out of compression range and would not have been loaded enough to worry about missing the stop for nitrogen bubble reasons. The fast ascent would have hurt you had you held your breath at all.
-Likely the swim upside down as you ascended helped in not getting hurt.
-The tanks do get bouyant as you use up the air. You gain a little over 5lbs positive bouyancy from the next to empty tank.
-when you hit the surface did you indeed have air in your bc? or did you have to put air in to float head above water.?
Did your dm come to the surface to assist you? As I am sure you blew by him/her.
Maybe give us a little more so we can give a little clearer info back to you. I am glad you did not get hurt. How did you enjoy it by the way? kev
ps. I am 5'8" 180lbs not much fat. I use no wieght with my steel back plate and 5lbs with my Zeagle wing using Al80 tanks. I am very relaxed when I dive now. Are you? This is the type of info that would be useful to help you with, ok.

 

[Bogie]

If there was no air in your bc you were under weighted.

Yes, your tank gets more buoyant as it empties. Air has weight, less air, less weight, more buoyancy.

Proper buoyancy check 500 psi at 10 to 15 feet neutral buoyant.

 

[stormchaser]

Hi Bud! Getting a rush like that is scary. Lots of things to consider from what you stated.
-Saying you had 22lbs of lead on you sort of means nothing until other info is added. For instance was your wetsuit new, full or shorty. Your own weight, are you slim or at a place where you may want to lose weight.(not sure how to ask that).
-When you state you hit 30fsw are you saying you where done the dive and ascending to your safety stop? or where you still multi-leveling your dive as usually done at Coz?
-I once watched a new diver trying to release air at the inflator hose and was actually inflating thinking he was letting air out. Did you maybe do this? Just asking as one generally doesnt blast that fast up if you have actually let air out.
-As a concern for your fast ascent I hope you where trying to blow air from your lungs as you ascended as to not embolize.
-One good thing for you is you likely where still out of compression range and would not have been loaded enough to worry about missing the stop for nitrogen bubble reasons. The fast ascent would have hurt you had you held your breath at all.
-Likely the swim upside down as you ascended helped in not getting hurt.
-The tanks do get bouyant as you use up the air. You gain a little over 5lbs positive bouyancy from the next to empty tank.
-when you hit the surface did you indeed have air in your bc? or did you have to put air in to float head above water.?
Did your dm come to the surface to assist you? As I am sure you blew by him/her.
Maybe give us a little more so we can give a little clearer info back to you. I am glad you did not get hurt. How did you enjoy it by the way? kev
ps. I am 5'8" 180lbs not much fat. I use no wieght with my steel back plate and 5lbs with my Zeagle wing using Al80 tanks. I am very relaxed when I dive now. Are you? This is the type of info that would be useful to help you with, ok.

New full wetsuit and I got a good beer belly going 250 pounds and I probably added some in Cozumel with all the cerveza. We started at about 80fsw and was multi level diving I was at 40fsw, got low on air about 750psi and started my assent. DM had the sting with the buoy I was following up. I couldn't hold on to the string. He stayed below. Because I am an air hog I am the last one in and first one up. I don't think I hit the wrong button because I was pulling on every exhaust string I had. You bet I was breathing....I was scared to death LOL I had an still have lot of trouble with buoyancy. The trip was great I got in 10 dives. Columbia Deep and Columbia Shallows and Santa Rosa Wall were my favorites so far. relaxed no but I am getting better.

 

[helimvee]

Was this your first dive on that trip with that gear setup? If so, did you add more weight on the following dives? If that was not your first dive, did you have any trouble on the previous dives?

 

[Bubbletrubble]

@stormchaser: Did you do a weight check after getting the new wetsuit and the 100 cubic ft. tank? How did you arrive at the 22 lbs. of lead?

 

[spt29970]

Perhaps the BC inflator valve was leaking or got stuck open. It is not too uncommon with rental gear, which is one reason I ALWAYS bring my own gear. With rental stuff you have no idea how well it has been maintained. Even so, with a stuck inflator you should have been able to vent air faster than it filled the BC. I know you were scared, but did you hear any air rushing into the BC during the ascent?

 

[LeadTurn_SD]

....One problem could be, is that I was over weighted ...

Possibly. Many new divers come out of basic OW overweighted.... sometimes grossly overweighted. Do an in water weight check before the next dive.

.... And still had a little air trapped inside the BCD?.....

Most likely. You were ascending, so any air you had in your BC at 80 feet expanded dramatically by the time you reached 30'. If you were overweighted, you may have had a good deal of air in the BC at 80'. If you did not start venting this air until you realized you were in an out-of-contral ascent, it may have been too late. Also, I've watched new divers hit the inflator button by mistake as they tried to vent, which compounds the problem.

Solutions:

1. As mentioned, do a good in-water weight check to make sure you are properly weighted.

2. During the dive, remember that any air you add at depth will expand during the ascent, so be prepared to vent it before you become positively buoyant. It is often easier to "stay ahead" of the buoyancy change by venting a little air as you first start to ascend. Remember, air can sometimes get "trapped" away from the dump valve, so it is a good idea to make sure it is at the highest point.... sometimes you'll need to "move" the bubble from one shoulder to another if air has become trapped (by dipping one shoulder, rolling on your side slightly, etc.).

Hang in there. It gets to be second nature with practice.

Best wishes.

 

[DandyDon]

-I once watched a new diver trying to release air at the inflator hose and was actually inflating thinking he was letting air out.

Seen it many times. My bud & just don't use that button much, preferring short dumps.

Proper buoyancy check 500 psi at 10 to 15 feet neutral buoyant.

Yep! And I like to make sure I can sink at that stage if needed.

New full wetsuit and I got a good beer belly going 250 pounds and I probably added some in Cozumel with all the cerveza. We started at about 80fsw and was multi level diving I was at 40fsw, got low on air about 750psi and started my assent. DM had the sting with the buoy I was following up. I couldn't hold on to the string. He stayed below. Because I am an air hog I am the last one in and first one up. I don't think I hit the wrong button because I was pulling on every exhaust string I had. You bet I was breathing....I was scared to death LOL I had an still have lot of trouble with buoyancy. The trip was great I got in 10 dives. Columbia Deep and Columbia Shallows and Santa Rosa Wall were my favorites so far. relaxed no but I am getting better.

New wetsuit has more buoyancy than an old one, even tho you didn't say what length or thickness it is - it'll still vary. We try to do local practice dives with all of our gear, real dress rehearsals, before every trip even after 9 years. It's not the same in FW with 7 mil vs SW in 1 mil, but we stay good with our BCs, etc. So was this your BC and did you dive it recently, or a rental?

I'm less than 250# but not a lot. If I wore a 3 mil in SW, I'd want 20# on an 80, 16# on a 100, but too close to call in comparison to you. Sounds like your need more quarry dives with your BC maybe, and more weight check dives on trip arrivals.

Was this your first dive on that trip with that gear setup? If so, did you add more weight on the following dives? If that was not your first dive, did you have any trouble on the previous dives?

Good question.

 

[TSandM]

The key to this story is almost certainly the weight check. And we can run back over a few basic concepts, too.

When you take a tank underwater with you, it has a lot of gas molecules in it, and although gas doesn't weigh much at atmospheric pressure, at the kinds of pressures that are inside of tanks, it does. In an aluminum 80, you have about five pounds of air that you intend to exhaust into the water (in other words, everything down to 500 psi). So you start the dive out five pounds "sinkier" than you end it -- that will be true, perhaps with different numbers, for every tank you ever use. Part of the weight you carry is to compensate for that air you lose, because the one thing you DON'T want is to end a dive positive, because then you can't control your ascent.

So . . . a weight check. If you are using a very light wetsuit, or no wetsuit, as many people do in Cozumel, you will want to weight yourself neutral at the surface with a full tank, and then add five pounds for the gas you are going to breathe. Neutral at the surface means bobbing up and down with the water pretty much at eye level, with an empty BC. The weight you end up carrying really consists of two things -- weight to counter the "floatiness" of your exposure protection (and sometimes of you, too, if you're a real floater), and weight to compensate for the gas. For me, in a light wetsuit, that means 5 pounds for the gas and 4 pounds for the wetsuit, for a total of nine. To carry 22 pounds would usually imply that you are either wearing a very thick suit, or that you are overweighted. Overweighted can result in serious buoyancy control issues, as the air in the BC expands and contracts with depth changes.

But also be aware that the biggest and most rapidly changeable air "bladder" you take into the water is your lungs. Since you're a good sized person, you have a lot of volume in those lungs. If you get a little floaty on ascent and get nervous about it, it's highly likely that you began to breathe rapidly and shallowly, with very full lungs. This makes you quite buoyant, and if you are properly weighted, full lungs will mean positive at the end of the dive, even with the BC empty. Anxiety causes a lot of buoyancy problems for novice divers -- at least it sure did for me!

What I'd recommend is to do a good weight check before submerging again. You could even play with that a bit tonight, if you're near the shore -- take a couple of weights to the water with you, and see how much it takes to sink you, or to sink you and your suit. When you add the gas (5 lb) and a couple of pounds for padding on your BC, you should have a rough estimate of where to start with your weight on the next dive.