Need to practise making safe ascents & descents

[gypsyjim]

Besides all the very good buoyancy suggestions above, have you tried descending and ascend in a horizontal, rather than in a vertical body position?

If you remain horizontal, this alone slows your upward or downward momentum, because of resistance. In the horizontal position, you can roll slightly to one side and pull your butt dump valve, if so equipped, which is more effective than the shoulder dump, to stop a rapid ascent. You can also quickly shift your feet into whatever position they may need to be in to make any corrections, should that be necessary.

 

[rongoodman]

If you're horizontal and start to rise too quickly, it's easy to go head down and kick while you're dumping air from the rear dump valve. If you're vertical, you can't fin down.

 

[gypsyjim]

If you're horizontal and start to rise too quickly, it's easy to go head down and kick while you're dumping air from the rear dump valve. If you're vertical, you can't fin down.

exactly.

Hi Ron.

 

[sabbath999]

The above horizontal advice is excellent, assuming you are not diving a drysuit.

 

[gypsyjim]

The above horizontal advice is excellent, assuming you are not diving a drysuit.

We were trained to do the horizontal ascent/descent also in the dry suit. You simply need to stay on top of the bubble in the legs, and vent the drysuit as you ascend.

 

[fjpatrum]

Another bonus is better off gassing with a horizontal body position, and the very slight exertion(as opposed to zero exertion of just hanging without movement).
DanV

I'm curious about this statement. I understand the exertion part of it but how would being horizontal help with off-gassing?

 

[satwar]

The key to good buoyancy control is staying on top of it ... in other words, learning how to be proactive rather than reactive. As soon as you feel yourself starting to rise or sink, you need to do something about it right away. If you are properly weighted, this is best done using your breathing. Think of your lungs as another ... smaller ... BCD. If you are starting to rise, breathe out while you are reaching for that BCD hose. It may be all that's needed to help you get your buoyancy back under control ... but remember that once you breathe out you need to breathe back in again, so keep reaching for that BCD hose. If, when you breathe in, you find yourself rising again, let a small amount of air out of the BCD to stabilize your position.

Conversely, if you find yourself sinking, breathe in while you're reaching for that hose, and equalize with a small squirt of air into the BCD while you're breathing back out.

The reason most folks have issues with buoyancy control is that they wait too long to do something about it ... usually because they're fumbling around trying to find their BCD hose, or accidentally grabbing a snorkel thinking it's the inflator hose. And by the time you're in a position to add or remove air from the BCD, you've changed position sufficiently that you have to do something dramatic to get yourself back under control. Skip the drama ... think of your lungs as a "first defense" against buoyancy issues, and use them first. It's a much quicker response, and usually enough to get you back to where you want to be.

... Bob (Grateful Diver)

Yes, I've learned that if I start to fumble for inflator I'm usually in trouble. A quick pull on my inflator hose is a very good technique.

 

[satwar]

Besides all the very good buoyancy suggestions above, have you tried descending and ascend in a horizontal, rather than in a vertical body position?

If you remain horizontal, this alone slows your upward or downward momentum, because of resistance. In the horizontal position, you can roll slightly to one side and pull your butt dump valve, if so equipped, which is more effective than the shoulder dump, to stop a rapid ascent. You can also quickly shift your feet into whatever position they may need to be in to make any corrections, should that be necessary.

I haven't tried butt valve dumping, will see how that goes.

 

[satwar]

I believe that you need to work on your weighting. Check your weight before a dive and after a dive (in a quarry or a pool). Use only enough for what you need to sink just below the surface, stay neutral at depth with minimal addition to your wing, and then at 15 feet. You should be able to get neutral at any depth. It's practice. But corking up is a problem. You say you don't realize this at times. Other than your gauges and surroundings, you ears are the key. You should be feeling minor changes as you change depth.

Good luck and safe diving to you.

I'm diving with 24 lb lead, with steel 100 cf tank. Wearing a 7mm core warmer over 7mm one piece plus 7mm booties, gloves & hood. Descending with a deep exhale and empty wing works well, but have to work at getting down with a 1/2 full tank.

 

[boulderjohn]

If, when you breathe in, you find yourself rising again, let a small amount of air out of the BCD to stabilize your position.

Conversely, if you find yourself sinking, breathe in while you're reaching for that hose, and equalize with a small squirt of air into the BCD while you're breathing back out.

Something that only comes with practice is knowing how much air to add or remove from your BCD when the time comes. In my experience with students, the tendency at first is almost always to overdo it in both directions. This results in a yo-yo effect.

When I was a pretty experienced OW diver, I got pretty good at knowing exactly how much air to add or subtract as needed. Working with students in the pool, I was similarly adept.

Then I started technical diving with steel doubles, BP/W, etc. I realized I was starting all over in this regard. It took me quite a while to avoid the yo-yo effect while doing decompression stops. As I ascended to the next level, I was so concerned about ascending past the stop that I tended to overdump and sink. Even though I have been doing this for quite some time now, I still think I have a way to go.

Just keep practicing. In time you will get the hang of it.