No Equalizing after 3x10m??

[tanteh]

Hi Outthere,

yesterday we visited a 10m diving tank. After some ecxercises I tried to dive 3x10m without breathing at the surface. During the third descent I felt problems due to lack of air to equalize. I had to stop the descent at 7m.

When descending to 30m, I understand, that, but what is in my case the difference between the first and the third attempt? I am used to dive 30m+, what happened?

Cheers, Carsten

 

[ivan]

hi

Wow very cool diving 10m 3 times. Never tried that one.

cheers

 

[fjohnson]

Just a theory but I would say you had no air in your mouth at the time and were you experiencing a contraction? If I have have a contraction and no air in my mouth it's very hard for me to equalize and does feel like I have no air to equalize with. The contraction seems to pull air away from where I can use it to equalize.

Fred

 

[donmoore]

Carsten,
It’s an interesting Phenomena. Although you were not lower than you would have been on a 30-meter dive, you didn’t have the air to equalize. The amount of air in your breathing cavities should be the same, but because of the extra length in time of going down and up three times you would have a greater carbon dioxide to oxygen ratio. The volume should actually be more because of less compression from depth.

Maybe somehow, with out knowing it, you pushed most of the air from your mouth into lungs. To solve it you would need to bring some air up into your nasal area from your lungs. Just a thought.

I never thought of going up and down multiple times on a single breath. I’m going to try it. Thanks for the thought.
Don

 

[Jersey Jim]

No equalizing after 30m

Tanteh:
I think the reason you had no air to equalize with after only 30' (3rd time) is that you expelled the largest volume of air during the first atmosphere (0-33'), into your mask to equalize. You paid that "air-volume penalty" 3 times instead of only once. The second and third atmosphere doesn't have the volume sacrifice like that first atmosphere does. And you lost it out of your mask all three times as it expanded when as you ascended.
So don't be discouraged. Your air loss sumulated deeper depths than the total you accumulated during that 30'.
Wish I had a 30' tank to dive in during the winter!
Take care,
Jim

 

[tanteh]

Hi,

thanks for all replies! I think all of you are right. Every answer sounded feasible. I will check it out next time. Unfortunately diving the tank is quite expensive and is only possible at distinct times. So it will take until summer to check it out again!

Cheers, Carsten