Dry suit uncontrolled ascent

[FinnMom]

Having trouble when at 6m or less in a drysuit and only 24 lifetime dives is not doing badly at all.

You describe having trouble sinking already at the start of your dive. Have you remembered that you will be even more bouyant at the end of your dive? Of you used 150 bar from a 12L tank, you used up about 2.3 kilos of air => you have that much more bouyancy. You need to add weight until you can sink (just barely, probably slowly but you definetly do sink) when you completely empty you lungs, suit and BCD/wing. After this, add enough weight to compensate for the change in the weight of your tank when it goes from full to 50 bar.

Other ideas
* The dump valves might becausing trouble by not venting well
* Your undersuit could possibly be blocking the dump valve from emptying as well as it could. Some people tape their suit flat or install a few small grommets at the site of the dump.
* Sometimes the air-in valve is very slowly, secretively leaking air into the suit all by itself. I had this problem and finally got the valve clean (sand I guess) so it stopped, then 6 months later I noticed it had started again and had to change the value to stop it.

 

[Bric Martin]

Hi everyone, I'm Dan from Norway.

I'm new to diving.

And instead of filling my suit, I will use my bcd.

Thoughts?

My mistake it looked to me as if he was adding too much air to the suit.

 

[EastEndDiver]

With only 8 dives under his weight belt and a new drysuit there may be "Task Loading" considering he may not have the simple dive basics mastered yet. For an experienced diver this might not come into play but looking at this situation it may.
Probably best to work on the drysuit issues in a pool with someone experienced watching and guiding your actions.

 

[pasley]

Weighting is usually a little bit more than diving wet. I highly recommend training in Drysuit diving. As you have already noted, when your feet get even slightly above your shoulders, the air bubble shifts and you ascend upside down. You have to learn techniques for recovering from this situation and other things. With all new things training by a qualified instructor and doing so in a pool before the ocean is recommended.

In general terms there are two schools of thought on how to dive a drysuit.
School 1 is to use the BCD only on the surface, descend by dumping the air out of the BCD, add only the amount of air to the drysuit required to maintain warmth. This should be by coincidence the amount you need to remain neutral. This technique gives you only one thing to deal with when maintaining your buoyancy.

School 2 it to use both Drysuit and BCD. Add only enough air to the drysuit to provide sufficient loft for warmth, and use the BCD for buoyancy control. This gives you two places to manage as you decend and ascend. Logically this technique would require more weight than the other technique.

In both techniques, add the minimum amount of air to the drysuit that is needed. The Drysuit is not normally filled completely up with air. Also by waiting too late to add air to the drysuit you become well, like a pound of vacummed sealed coffee. Try to avoid that.

 

[Storker]

School 1 is to use the BCD only on the surface, descend by dumping the air out of the BCD, add only the amount of air to the drysuit required to maintain warmth. This should be by coincidence the amount you need to remain neutral. This technique gives you only one thing to deal with when maintaining your buoyancy.

School 2 it to use both Drysuit and BCD. Add only enough air to the drysuit to provide sufficient loft for warmth, and use the BCD for buoyancy control. This gives you two places to manage as you decend and ascend. Logically this technique would require more weight than the other technique.

Uhh... What?

No.

 

[Reku]

Logically this technique would require more weight than the other technique.

Using bcd and drysuit together does not require more lead than just using the drysuit.

Why would you ever think it would require more???