Safety stop - loosing my buoyancy

[Pink rach]

Hi, I'm a relatively new diver who has about 20 dives logged and am an advance d open water. My buoyancy is improving which I'm happy with but I'm having trouble with it when were close to ending the dive. I can use my breath to get down and use it as and when needed during the dive to control myself. The problem I'm having is when we come up to the 5 meter safety stop I cant seem to control it. I struggle to stay at the safety stop for the specified time and find myself floating up. I realise the importance of the safety stop and enjoy diving and want to get up to dive master but I can't figure out what I'm doing wrong and its frustrating. Any advice would be greatly received

 

[2airishuman]

In general it is harder to control buoyancy at shallower depths and it is also harder to control buoyancy without a visual reference (such as a nearby bottom). If you're floating up, you'll have to dump some air from your BC even if you would prefer to control your buoyancy with breath alone.

If your BC is completely empty at this point and you can't dump air, then you're slightly underweighted.

Also, are you in horizontal trim? If you are trying to do your safety stop vertically, then unconscious finning will propel you towards the surface...

 

[Scott]

Without being there to see my first instinct is you are under weighted
When conducting your safety stop what is the pressure of the cylinder you are using?.
At the end of the 3 minutes if your cylinder is at 35 bar / 500 psi, with no air in the BC and breathing normal you should be able to maintain the stop. Let's just say you being the stop with 50 bar.
It could also be you have a small amount of gas trapped in the BC somewhere. Depending on your position, horizontal or vertical, make sure you have all the gas vented.

 

[Steve_C]

Practice shallow. When doing a quarry dive (or shore dive) practice in ft of water. Personally I check my weighting with my tank at 300 psi and in 5-9 ft of water. Want to be able to hold the depth with BCD essentially empty.

 

[Lorenzoid]

Are you really on Utila as your profile says? If so, there are people there who would be glad to work with you. You don't have to be in a course to get an instructor or DM to work with you--many will do some coaching on the side.

 

[Rred]

I'm betting the OP has one of them popular cheap aluminum80 tanks. And the problem is not that you are shallow, not that you are doing the safety stop, but that those cheap Alu80's have positive buoyancy when they are nearly empty, which is the case when you are making a safety stop.

As was said, you're probably underweighted. Not by much, but maybe 2-4 pounds.

Which is one reason I prefer a steel tank. It doesn't save me anything in weight, but it puts the weight in my tank, instead of on my belt, and allows me to store another ~15% more air on my back at the same time. Which is a nice free bonus, from my point of view.

I'd try the next dive with one more weight (2-4#, whatever's around) on the belt, along with trying to ensure there's no air in the BC at that point. Or try a steel tank--you may find you like them.(G)

 

[outofofficebrb]

All good points above. I dive locally with a steel tank and it helps with what @Rred mentioned but sometimes when you are vacation diving (most of my dives), all that is available are AL80s. If you've tried all of the suggestions above and your BC is empty during safety stop, try adding some weight. Minimal.

Your breathing has a very large impact on your buoyancy even at a safety stop. That's also something to think about.

 

[tomfcrist]

And the problem is not that you are shallow, not that you are doing the safety stop, but that those cheap Alu80's have positive buoyancy when they are nearly empty,

AL 80s are positive when nearly empty, however that has zero impact on a properly weighted diver.

Weight of air is universal, thus as you breathe down any tank it gets lighter and affects buoyancy. The weight shift is more dramatic for a diver using a steel 100 than it is for an AL 80 diver.

The buoyancy problems arise from how and WHEN a diver assesses "proper weighting". The gold standard is to be able to maintain neutral buoyancy at 15' with a nearly empty tank. If a diver decides to assess their buoyancy with a full tank at 15', they will be 7+lbs light when at the end of the dive when trying to do a safety/deco stop.

You should feel heavy on decent and perfect on ascent.

 

[rongoodman]

When you're able to start doing your stops flat in the water it's very easy to go head down a little and drop with just a kick or two. If you're vertical, the only direction you're going to go when you move your feet is up.

 

[TMHeimer]

As Steve_C said, practice shallow. When I am finishing up my shore dives I sometimes like to see how close I can come to the surface swimming back in without hitting the surface (maybe 3 feet below?).