planning a deco dive

[supergaijin]

Me and a friend have been discussing doing a deep dive to perhaps 60 metres on air. I realise this is fairly dangerous but not unheard of. Our reasons? Just to see what happens really. My deepest previous dive has been to 40m.

Can somebody point me in the direction of an informative site or thread where this has been discussed?

much appreciated

 

[Jason Ooi]

Hi,

If you thing go for deep diving, thing "wisely" consider technical trimix dive courses.
Don't use single back gas for 60m depth dive, you must know your SAC rate before plan the dive.

play safe dive safe

Me and a friend have been discussing doing a deep dive to perhaps 60 metres on air. I realise this is fairly dangerous but not unheard of. Our reasons? Just to see what happens really. My deepest previous dive has been to 40m.

Can somebody point me in the direction of an informative site or thread where this has been discussed?

much appreciated

 

[Vie]

If you are planning a bounce dive on a single tank - JUST DON'T DO IT!

http://www.cisatlantic.com/trimix/text/wahwah.txt

 

[andydiver06]

Training is the best option.----Deep air diver course. I have read that earlier lot of people use to dive in the range of 50-60 m with air. If you don't get narced and do something foolish maybe you will survive. Your PN2 at 60m will 5.53 which way beyond dagerous narc zone . Your PO2 will be 1.47 (you can get O2 tox) Try your dive profile on V-Planner. You dive plan may look something like this if you plan a 20 min dive.
descent to 60m - 4 min (4) , bottom time 16 min at 60 m(20), ascend to 33m @ 9m/min (23), Stop at 30 m 2 min(25) , Stop at 27m 2 min(27) , stop at 24m 2 min(29), stop at 21m 3 min(32), stop at 18m 3 min(35), stop at 15 m 5min(40) , stop at 12m 6 min (46), stop at 9m 10min(56), stop at 6m 15 min (71), stop at 3m 24 min(95), surface at 9m/min.... total dive time - 95 min. You are going to need plenty of gas.
I have never done more than 40m dive. Just ran your profile through V-Planner for fun..

 

[Packhorse]

Our reasons? Just to see what happens really.

"Why did you put a loaded gun to your head and pull the trigger? Just to see what happens really. "

 

[El Orans]

If you don't get narced and do something foolish maybe you will survive.

You will get narced.

 

[Jason Ooi]

I agreed....."PLEASE DON"T DO IT"

You will get narced.

 

[grazie42]

Please go to www.thedecostop.com and ask the same question...the answers won´t be so sugarcoated...

 

[espenskogen]

If the dive is planned well, and you work up to the depth, it's perfectly doable. Sure, you'll be well narked. But it's doable. What is not advisable though, is to go from a 40 m no-deco dive to a 60 meter deco dive. Work your way up - Do 35 meter deco, then increment in 5 meter steps.

You need to consider gas planning (how much gas are you planning to bring), accellerated deco (possibly), thermal protection (an hour of stops are gonna make you cold - Where are you planning to do this?)

I have done 55 meters in the UK, and it really isn't that bad - I mean we have bad viz and cold water, but if you're prepared for it, then that's cool.

You will need an advanced nitrox cert, and I recommend you'd be comfortable diving twins (With everything that goes with that - Shutdowns etc)

As I say, if you plan it well, and know what you're doing, 60 meters on air is fine. Don't worry about the tox thing someone mentioned earlier - It's not going to be an issue with the exposure you're looking at. (Not to mention that the narcosis actually reduces the chance of O2 tox.)

Oh, and go take some technical training if you haven't got it already. A 60 meter air tech dive done the right way is reasonably safe. But a 60 meter dive without the training isn't tech, it's just stupid.

 

[espenskogen]

If you are planning a bounce dive on a single tank - JUST DON'T DO IT!

http://www.cisatlantic.com/trimix/text/wahwah.txt

The wahwah article you referred to were for dives well below 100 meters, and PPO2 of 2.5 and above. Now that is silly deep on air. 60 meters - Within limits on air. (Extended range certifies you to 55m on air.)