Out of Air

[dkktsunami]

With all of the rental equiptment I've used (tending to be inexpensive (unbalanced?), and used usually on non-deep dives), it seems to always get harder to breath around 300-400 psi. This usually tends to warn me it's time to start to ascend.

James, You need to be ascending long before "it gets hard to breathe". You've got a buddy with you - think how difficult it will be to breathe with two of you sucking on the same tank in an emergency. Need to watch pressure gauge and go up according to your plan, not when hard breathing warns you. 300 psi is too low for safety. Have a bunch of fun and be safe. Dave

 

[Damselfish]

With all of the rental equiptment I've used (tending to be inexpensive (unbalanced?), and used usually on non-deep dives), it seems to always get harder to breath around 300-400 psi. This usually tends to warn me it's time to start to ascend.

the common rule of thumb (for basic recreational diving) is to be up with at least 500PSI.

"hard to breath" hasn't been the rule since the days of J valves and no SPGs. I assume your rental gear has a SPG?

 

[stevetim]

Concur!

Personally, this is one reason why I prefer to use my own gear. (not sure that is practical given the "travel" described above...)


~m

Of course everyone knows "my gear" never has a chance to fail. Don't fall into a false sense of security and think your own gear will never fail. I think "experienced" divers have a sense of how much air they consume at depths vs. time and would question the gauge if it was stuck on a certain pressure for any amount of time, especially at 35m where the needle is going to move a little quicker than normal. Being a novice diver myself, I check gauges frequently and can take a pretty good guess where my spg needle should be throughout a dive(considering "my gear" isn't failing....)

 

[Rafael]

Happy to hear your are fine, well done buddy, panic is divers #1 killer

 

[Pietfer]

I found this article by Basie Ackermann in a spearfishing site, gruesome but I think relevant. We (certainly myself) can learn something from this incident.

(05-Jan-06) Report on Diving Death by Basie Ackermann

Francios Swanepoel's (single - staying in Scottburgh after moving down from Free State a couple of months ago) body was found off Scottburgh main beach round about the 5th December 2005 - I was on the beach when it happened, but not 100% sure of the date. It was in that week. It was seen floating on backline, lifeguards went out on a duck to tow the body back to the beach - badly bloated and decomposed. Face and hand were eaten away by crabs etc. (had been in the ocean for 2 weeks), but body intact in wetsuit and weight-belt still on. I couldn't see any signs of a shark attack, even post mortem. No bite marks.

My take on this (knowing the area extremely well - I live here, and dive Back Beach very regularly):
Taking into consideration the extremely rough conditions on the day he went missing (big easterly swell and 20knot east), his inexperience (only been diving a couple of months) and the big rip he swam out in off Back Beach, his weight belt (+-10kg!) still being on when found and reports from people seeing him struggle. My opinion is he drowned due to either; 1) Panic - realizing surf was way too rough for him and trying to swim back against the rip -( his float never made it past backline, and gun was unloaded when found on beach just south of where he swam out) and then drowning or 2) due to a medical reason brought on by exertion of swimming in rough seas, and drowning.

For a fact I can tell you that there was no shark attack, as reported by the over- zealous, ill-informed and sensationalistic media, and the sad turn of events boils down to lack of experience, in my opinion. He should never have dived in those conditions - none of us down here even considered it a diveable day and he was way overweighted. It is a great pity. Condolences to family and friends.

Basie Ackermann

 

[Iruka]

Hm, is there a way to study this more accurately, since according to PADI dive tables, any 35m dive is a deco dive. I need to know more about this!

Hi Mislav,
Actually, using the PADI tables (unless you have them from 15 or 20 years back, I'm not sure about them) 35m isn't a deco dive. It IS a "mandatory safety stop" depth, as is anything over 30m/100f.

Of course, if you are diving a "square profile" a dive to 35m becomes a deco dive very quickly....don't have the table in front of me, my wife's reorganizing again, haha, but somewhere around 12~14 minutes is the NDL. Of course, around here everyone does multi-level profiles.....so even dives, that are, say...40m for an hour are not "deco" dives, because you're continually ascending, and might be spending the last 30 minutes or so around 6~8m. That's the nice thing about tropical diving....in most cases, you have a sloping reef to work your way up, and dive as long as you have enough air & until the boat crew starts banging wrenches on the ladder to get you back on board. I had a dive once to around 40m which lasted 1:45....day off beach dive, so nobody in a hurry to get back & I could take all the time I wanted.

 

[mislav]

Hi Chris and thanks.

Yes, I am talking about the "square profile" since that's the only thing PADI has taught me at this point. Might be that my OW class was lacking or that I really couldn't have more knowledge about it with OW only. I'm not sure which is it, but still I'd like to learn more on this. How do I do that? I'd like to have a better understanding of this regardless of whether I'll be diving at that depth or not.

 

[CraigDiver]

I'm very surprised that nobody has mentioned air integrated computers. I always dive with my own regs which includes a mechanical pressure guage and an electronic one (as part of an air integrated wrist computer). Therefore diving with 2 completely independant pressure guages.

I am amazed at how complacent some of the divers seem in there posts about ascending with minimal air. Anything could happen - you should have a thrid of your air left upon surfacing.

 

[Damselfish]

Anything could happen - you should have a thrid of your air left upon surfacing.

In some diving, but in an easy rec dive that's usually overkill. A lot of dives like that people are piddling around under the boat or near shore by then.

 

[IslandCowgirl]

Pietfer,

Great job at keeping your head and not panicing. Excellent work at implementing the skills that you learned while continuing your education. May your next dive be uneventful.

H- the Island Cowgirl