New Experience in Pond

[mike_s]

Still waitin' to hear how the jeep was sunk? heh.

 

[av8er23]

I have not heard anything today about it? Assuming it is still at rest in the bottom of the pond.

 

[pasley]

... Is a rapid acent from a depth of 25 feet potentally dangerous? I know it is not good but is it very likely that you could get an embolism from this depth?

This is from Divers Alert Network (DAN) website under FAQ:
...For a diver at 15 fsw/4.6 msw, the total pressure acting on his body is 1.5 atmospheres (one atmosphere at the surface, plus an additional 0.5 atmospheres exerted by the water column). A sudden ascent to the surface would therefore result in a 30 percent pressure reduction, and assuming a compliant chest wall, a volume increase of 50 percent. Lung injury may result.

Actual volume changes may be less than this because of the effect of the surrounding chest wall to provide some rigidity and protection for the lung. However, if the same vertical change occurred from a depth of 66 fsw/20 msw, the 0.5 atmosphere of depth change would only result in a 16 percent reduction in pressure and a 20 percent increase in lung volume, and would be less likely to cause lung injury. Boyle's law thus explains why abrupt changes in depth while in shallow water can be far more hazardous than equivalent changes of depth in deep water.

Bottom line, a rapid asscent from even 10 feet can be "not a good thing". :11:

 

[teknitroxdiver]

And even more to the point of that article....a 10 foot ascent from 10 feet to the surface would cause far more expansion of volume in your lungs than a 10 foot ascent from 200 feet to 190 feet.

 

[av8er23]

Makes sense.. This would not apply to free diving though would it?

 

[Don Burke]

Makes sense.. This would not apply to free diving though would it?

The problem of embolism is compressed gas inhaled at depth expanding on ascent.

Unless we can figure out how to get more gas into a free diver, it is not an issue.

 

[scubafool]

.Controlling the beast in your head when you get in 0 vis is MANDATORY! The adrenalin rush an panic attack when that beast raises it's head are probably the largest cause of diver deaths. You start making really BAD decisions and things can go from uncomfortable to fatal in seconds.

Uh huh, I have felt the beast start to run around inside of my head before, and let me tell you, that is NOT a good feeling when you are underwater. I know for a CERTAINTY that had I not removed the stressing factor when I did, I would not have remained in control of myself much longer. In zero viz, you might not have any idea what the problem is, though, and the lack of any point of visual reference can be really disconcerting. I am so grateful that av8er23 has decided to forgo a repeat of the original dive.

 

[Snowbear]

For a case of someone who had a reality check about entanglements and a diver's ability to free her- or himself, see this thread :11:

 

[Hank49]

OK, I have learned what I need to from this situation. I am not ready to do something like this. I will leave it up to someone else. Thanks everyone for the great inputs.

av8er23, I apologise for having given advice as to how I would have tried to slavage the jeep. I surely didn't want you to get killed trying. Maybe I'm a dying breed. But if my 16 year old son told me all he had to do was find and pull a jeep out of a pond and it would be his?..."go for it son". I'm sure he could pull it off safely. Everyone is talking about how dangerous the pond is....well, it's a wonder I'm still alive because I must have swam in about 20 of them growing up..not to mention jumping off bridges into rivers and creeks....building tree houses that were 80 feet off the ground, a swing that was 90. I swear, if I'd joined SB before I started diving, I probably wouldn't have started with all the posts about dying...America has changed.

 

[Chris Sawallich]

The problem of embolism is compressed gas inhaled at depth expanding on ascent.

Unless we can figure out how to get more gas into a free diver, it is not an issue.

This analogy was taught to me by an instructor I admire very much.. Think of a Soda bottle when you shake it up... Thats youre tissues at depth on gassing.. Now think of taking the cap off of the soda bottle very slowly.. That your tissues off gassing on a controlled accent..

Now think of taking that cap of VERY FAST... That would be your tissues exploding on an uncontrolled accent.. next step... You are bent.....