Just call me a cork or dork. . .they both apply . . .

[BettyRubble]

Ok so I've been frustrated by my inability to control buoyancy when I hit the 18-20 foot range. I've popped up so many times, that now my dive buddies joke that if they lose sight of me they just need to look up. . .UGH . . . obviously this could be a very serious issue so I need to work out the kinks. So far I'm diving fairly shallow so missing the safety stop (cuz I go from 18 feet to surface uncontrolled) hasn't killed me yet, but at greater depths or more frequent dives this is going to get me in trouble.

Sooooo this weekend a light bulb finally went off and I figured out two things. It helped and I managed to hold 3 safety stops after that.

1) Instead of proactively dumping air in anticipation of the pressure change, I realized that I was just REACTING to my body starting to ascend by dumping air. By waiting to react it was too late, I couldn't get the air dumped fast enough to prevent the cork response and I'd find myself at the surface. Now I am proactively dumping air around the 22-24 foot mark.

2) I finally figured out (with the help of my buddy - thank you Rich!) that in order for my shoulder dump to work properly, that I must tilt myself so that shoulder is the highest point and the air bubble will escape from that valve. I'd like to say the reason I hadn't figured that out before was cuz I'm so good at being horizontal in the water!! Ha Ha!!

But seriously, what else am I missing? I'm weighted fairly right - maybe a pound over . . and buoyancy below 18 feet is fairly good. (well at least it is improving).

So for now my biggest issue in diving is this one. Any other suggestions are greatly appreciated!

 

[HenrikBP]

Good finds and good thinking Pam.

I'm having similar issues. I have a hard time managing both the wing "bubble" and the dry suit "bubble" at the same time.

- I think you've found the main issue; thinking ahead rather than reacting when you notice you're heading up.

- you may have an easier time at fine tuning buoyancy if you also use lung volume for control.

- Descent/ascent drills are great way to work on this. Not the most interesting dive, but great practice.

Good on you for continuing to think and practice

Henrik

 

[TSandM]

Anticipation is a huge part of it, but so is practice. Even when I began to anticipate better, I didn't have any sense of how much to dump, so sometimes I'd underdo it and cork, and sometimes I'd overdo it and be unable to ascend. It took time. (Oh, and BTW, I did my first successful safety stop in a drysuit on my 50th dive, so you are not alone in having this kind of problem!)

In some suits, if the dump is situated properly, all you have to do is hold your arm in the right position as you go up, and the suit will more or less auto-dump. (This only works for controlled ascent rates, though, because dry suit dumps are relatively slow.) This was true for my Mobby's suit, and is true for my Fusion (but was not for my Diving Concepts suit, which required more of a whole body motion).

I've also found that my wing dumps fast, and doesn't require a lot of expansion of the air to be able to dump it. But my dry suit is hard to vent if there isn't much gas in it. So, as I begin to ascend, I start by dumping the wing. After a couple of times doing that, the gas in the suit has expanded to where it is easy to dump. If you are fine-tuning your weighting very closely, you will find that, with an empty tank, you don't have a lot of gas in either place, and it's harder to get what you have out. I've actually found about 2 pounds extra makes life easier, because there's enough gas in the suit to move it up to the shoulder and dump it easily.

 

[BettyRubble]

Thanks Henrik!! Once I figure out that pesky 18-20 foot issue, maybe I can master the 30-20-10 . . .

 

[BettyRubble]

Anticipation is a huge part of it, but so is practice. Even when I began to anticipate better, I didn't have any sense of how much to dump, so sometimes I'd underdo it and cork, and sometimes I'd overdo it and be unable to ascend. It took time. (Oh, and BTW, I did my first successful safety stop in a drysuit on my 50th dive, so you are not alone in having this kind of problem!)

When the light bulb went off my first thought was - why the heck hadn't I thought of that sooner!! I have to remind myself I am only 27 or so dives into this adventure.

You are right about over dumping issue too . . . when I use my rear dump valves (my buddies wonder why my arse is always in the air), I tend to overdump. . so I am hoping that having figured out my shoulder dump I'll find the right balance. . . practice practice practice.

I like Henrik's idea of practicing this weekend. Fortunately I have very patient dive buddies . . .

 

[tedgarner]

How often do you dive? The more you dive the better you get a control.
Also remember your lungs are a great way to control you buoyancy. When you are at your safety stop get all the air out of you lungs before you next breath.
I get all the air out of you BC well before safety stop or I would do the same.
Are you sure you are a pound over or a pound under. test it next dive. I would rather put air in BC at depth than pop up at end of dive.
One thing i fight is that I am not a lean person so i float better than most people.
Sometimes women that look like they don't need alot of weight do because of body fat in all the natural places, and less muscle mass than a man.
Those are just some ideas I have hope it helps

 

[dkktsunami]

Thanks Henrik!! Once I figure out that pesky 18-20 foot issue, maybe I can master the 30-20-10 . . .

Have you done a proper weight check? You want to do this at 10' with 500psi (in AL 80) and no air in your bc. Your proper weight will be the minimum amount to allow you to hold this position without drifting to the surface. If sinking you have too much weight, rising, too little. The idea here is to carry as little weight as possible yet be able to perform a safety stop at the end of your dive when your tank is nearly empty.

 

[BettyRubble]

How often do you dive? The more you dive the better you get a control.
Also remember your lungs are a great way to control you buoyancy. When you are at your safety stop get all the air out of you lungs before you next breath.
I get all the air out of you BC well before safety stop or I would do the same.
Are you sure you are a pound over or a pound under. test it next dive. I would rather put air in BC at depth than pop up at end of dive.
One thing i fight is that I am not a lean person so i float better than most people.
Sometimes women that look like they don't need alot of weight do because of body fat in all the natural places, and less muscle mass than a man.
Those are just some ideas I have hope it helps

I was cert'd in June and have managed to get in 20+ dives since - about 1/2 ocean and 1/2 quarry. So I'm diving fairly frequently at this stage and have a number of trips lined up for the next few months.

Good point about emptying lungs at safety stop - I've been working on lung control but am still way off.

Yes - I've been working on weighting alot the last few weeks. I think once I master the cork issue I'll be able to drop 1-2 pounds.

You bring up an interesting point - we women have a different AND changing mass. Which is why we have a 'fat end' of the closet and 'skinny end' of the closet. For me it is a 10 pound swing from season to season but I hadn't thought about how that affects my weighting . . Hmmmm .. a new area for me to test!

 

[BettyRubble]

Have you done a proper weight check? You want to do this at 10' with 500psi (in AL 80) and no air in your bc. Your proper weight will be the minimum amount to allow you to hold this position without drifting to the surface. If sinking you have too much weight, rising, too little. The idea here is to carry as little weight as possible yet be able to perform a safety stop at the end of your dive when your tank is nearly empty.

Yes and no. :blinking:

Only come up with less then 800 psi once (after a mishap) so I've not done a check at 500 psi. (Being a woman my buddies breathe more air then I ) But I've done several checks. I got down to 10 lbs in 7 mil/fresh but had to go back to 12 lbs because of not holding the stop. I think, if I can master the other issues causing me to cork, that I can actually get to 10 lbs and safely hold a stop.

 

[ScubaDocER]

When the light bulb went off my first thought was - why the heck hadn't I thought of that sooner!! I have to remind myself I am only 27 or so dives into this adventure.

You are right about over dumping issue too . . . when I use my rear dump valves (my buddies wonder why my arse is always in the air), I tend to overdump. . so I am hoping that having figured out my shoulder dump I'll find the right balance. . . practice practice practice.

I like Henrik's idea of practicing this weekend. Fortunately I have very patient dive buddies . . .

Congrats on being able to resovle a very important issue. Being able to maintain your ascent rate and buoyancy control in shallow water can be very challenging. I like the idea of using my rear (arse) dump. It allows me to remain horizontal throughout my ascent. The key, IMHO, is to give it a SLIGHT tug. Barely pull on the cord and release it immediately. When you put your butt higher than your shoulders the air will collect nicely near that dump. It does not take much for the air to escape when you pull on it. I have learned that whenever I use this dump I almost always let out too much air. No matter how small the tug. That's ok. Use your inflator hose and tap it twice. Maybe thrice And you should be neutral once again without having to be out of trim. As others have stated, it takes practice to get it just right. Try it on your next dive and see if it works for you.

The only issue I have with using the shoulder dump is that you have to get out of trim to lift your shoulders. Since all of the air is now at your shoulders you'll start to rise in the water. Especially if you were previously neutral in a horizontal position. After dumping the air, if you wish to return to a horizontal position then you may find that you are higher in the water than you intended to be. It does work, just takes lifting your shoulders and then returning to a horizontal position. To me it is easier to remain horizontal, use your butt dump, and then return to a neutral position adding a little bit of air as needed. Let me know if it works for you.