Scuba Quiz

[gamon]

Every so often an interesting question arises in regard to scuba diving and I run it by a few people to see if they can get it right. I may add more to this thread depending on how it goes that's why I didn't make a poll out of the one question it's more of a discussion thread.

Here's one that's been circulating on a FaceBook scuba group.

You're in a car that goes off the road and you sink in, say 50' of water. The windows are closed or mostly closed and the car is rapidly filling with water. You take a deep breath of air that remains in the vehicle, exit the car and swim for the surface.

The question- If you don't exhale on the way up are you at risk for type DCS (ruptured lung and arterial gas embolism).

 

[johndiver999]

Depends on Bill Gates.. well actually it depends on Windows. Are they open or closed?

 

[gamon]

Windows mostly closed, car filling with water.

Original post updated thank you

 

[Coztick]

This is a freedive.
No gas volume was added at depth so no need to exhale to ascend.
Any gas volume in the lungs would actually increase buoyancy speeding the ascent.

 

[Coztick]

This is a freedive.
No gas volume was added at depth so no need to exhale to ascend.
Any gas volume in the lungs would actually increase buoyancy speeding the ascent.

Ok, part b changes everything...
Now you've inhaled pressurized gas at depth.
Ya gotta exhale or yer gonna 'splode!

 

[gamon]

This is a freedive.
No gas volume was added at depth so no need to exhale to ascend.

Not correct but in all fairness you may have read my post before I updated it to say that you take a breath from the air remaining and then exit the car and swim for the surface.

 

[johndiver999]

If you don't take a breath from the air in the car, your lungs will still contained compressed air and will be at a high pressure, so the lungs will definitely expand on the way up if you don't exhale..

 

[Jafo19D]

Depends. Is this a hatchback or SUV?

 

[gamon]

If you don't take a breath from the air in the car, your lungs will still contained compressed air and will be at a high pressure, so the lungs will definitely expand on the way up if you don't exhale..

I don't believe this to be true. If the air in your lungs was inhaled at the surface, then the lungs will simply compress as the car sinks and then inflate to the same point they were at before the car sunk. So yes, the lungs will expand on ascent but only from their compressed state- not any more than they were to start off with.

 

[wheeledgoat]

yeah, but you're not going to have held your breath from the moment of the car impacting the water at the surface. you're going to keep breathing until you can't, i.e. the car has filled with water, which will be at depth, at pressure. this is a cesa situation and you'd better exhale on the way up!