OK to Bounce Dive to 220 Fsw as...

[David_57]

Amazes me how anyone could consider 220ft on a single 80 cuft tank with perhaps 20 dives under their belt a safe dive!!!

 

[stargost]

I was havind a triple scotch before my 3rd dive of deep speciality when the OP asked the question, but when he left, the instructor was also syaing that it would even be more fun to bounce to this depth with Nitrox (... kidding ...)

Serious (maybe) : the students were indeed just passing their Padi AOW, because they needed a PADI card to rent equipment. In reality, they were CMAS 4, with 2000dives, and were physician carrying on special test, under lots of supervision

I try to locate the document I got from Rubicon-foundation about a ~16yo or something teenager who by accident bounce to some very deep depth (80m I think), had the proper thinking to dump his weight and swim back to surface, and survived without damage (but i think he went to a chamber). Sorry I can't get the link.
Maybe the point here is that if this kind of event happens, you can survive ....

 

[SCUBA_Phil]

If you going to bounce dive do it right, 330' with a steel 100 cuft

Decompression model: VPM - B

DIVE PLAN
Surface interval = 5 day 0 hr 0 min.
Elevation = 0ft
Conservatism = Nominal

Dec to 200ft (4) Air 50ft/min descent.
*Dec to 330ft (6) Air 60ft/min descent. <<< High pp
*Level 330ft 0:50 (7) Air 2.31 ppO2, 330ft ead <<< High pp
*Asc to 90ft (15) Air -30ft/min ascent. <<< High pp
*Stop at 90ft 1:00 (16) Air 0.78 ppO2, 90ft ead <<< CNS high
*Stop at 80ft 1:00 (17) Air 0.72 ppO2, 80ft ead <<< CNS high
*Stop at 70ft 2:00 (19) Air 0.65 ppO2, 70ft ead <<< CNS high
*Stop at 60ft 1:00 (20) Air 0.59 ppO2, 60ft ead <<< CNS high
*Stop at 50ft 2:00 (22) Air 0.53 ppO2, 50ft ead <<< CNS high
*Stop at 40ft 3:00 (25) Air 0.46 ppO2, 40ft ead <<< CNS high
*Stop at 30ft 3:00 (28) Air 0.40 ppO2, 30ft ead <<< CNS high
*Stop at 20ft 15:00 (43) Air 0.34 ppO2, 20ft ead <<< CNS high
*Surface (43) Air -30ft/min ascent. <<< CNS high

Off gassing starts at 140.7ft

OTU's this dive: 28
*CNS Total: 435.4% <<< CNS high

97.5 cu ft Air
97.5 cu ft TOTAL


DIVE PLAN COMPLETE

Go big or go home
This plan has positive margin (2.5 cuft of margin)

 

[gr8fuldiverNC]

I'm just glad ScubaBoard wasn't around when Jacques Cousteau was getting started. After reading a couple of the threads on here he may have given up on his ideas, inventions, and explorations once he realized he could die on almost any dive and everything he was probably doing was against the "rules".

I would imagine there are plenty of old bold divers. They just don't hang out on ScubaBoard.

Didnt Jacques lose a son that way? I imagine he wouldve loved the opportunity to do that particular dive over, armed with the knowledge we have now. From your previous posts, Im guessing you have no technical, or even professional level (not that thats a substitute) training, and if you do, you obviously didnt learn even the basics of safe deep diving. I hope your diving isnt as reckless as your statements on this thread. We have all done stupid dives, the smart people learn from it, and certainly dont encourage others to try. That kind of attitude on a boat Im working will earn you a nice dry bench for the duration of the trip.

 

[ScubaInChicago]

Didnt Jacques lose a son that way?

No,

Jacques-Yves Cousteau - Wikipedia, the free encyclopedia

On 28 June 1979, while the Calypso was on an expedition to Portugal, his second son, Philippe, his preferred and designated successor and with whom he had co-produced all his films since 1969, died in a PBY Catalina flying boat crash in the Tagus river near Lisbon. Cousteau was deeply affected. He called his then eldest son, the architect Jean-Michel Cousteau, to his side. This collaboration lasted 14 years.

 

[BDSC]

Didnt Jacques lose a son that way? I imagine he wouldve loved the opportunity to do that particular dive over, armed with the knowledge we have now.

Really? I know he had one son that died in a plane crash. Which one of his sons died in a diving accident?

From your previous posts, Im guessing you have no technical, or even professional level (not that thats a substitute) training, and if you do, you obviously didnt learn even the basics of safe deep diving.

You are right. I have not had any training beyond AOW. Even though I have been on numerous deep dives (130 ft or below), I realize that I am lucky to be alive. I could have easily died on any of these dives. I know my "blind luck" will run out one day. Thanks for pointing it out. You may have saved my life.

I hope your diving isnt as reckless as your statements on this thread.

It is. I am lucky to be alive.

We have all done stupid dives,

I have done one stupid dive. Went to 233 ft. on a single Aluminum 80. If you have done at least two stupid dives then you have done at least twice as many as me. You are lucky to be alive!

and certainly dont encourage others to try.

I have never encouraged others to do stupid or dangerous dives. Going to 130 ft. on air is neither stupid or dangerous.

That kind of attitude on a boat Im working will earn you a nice dry bench for the duration of the trip.

Make sure you let me know which boat you work on so I won't make the mistake of going on that boat. That way it won't be on your record when my luck runs out and I kill myself doing stupid and dangerous dives.

 

[Nemrod]

I was sitting at a table of beginner and newly acquired advanced level divers (they were rewarded their advanced cards at dinner) the instructor told one of the divers it would be fine to drop down to 220 and come right back up&#8230;

What are the issues here especially if the diver is pretty overweight and out of shape&#8230;

An unplanned dive to that depth by a neophyte would likely result in a date with a wheelchair."Bounce" dive is an a misunderstood concept. A single dive to some depth is not really bounce diving. Multiple descents and ascents as occur, as an example, with scuba equipped spear fisherman on the rigs in the Gulf are closer to bounce diving, up and down, up and down and up, over and over. There is nothing unsafe about a single, short dive, but, of course, one to 220 feet without deference to deco obligations sounds like a good way to get a good fizz going in the old spine. But gotta sell wheelchairs to somebody.

I have a relation by marriage that is confined to a wheelchair for exactly that reason, bouncing fish on the rigs at depths over a 100 feet, repeated, multiple, short dives without tracking his deco. One time to many.

YRMV, I suspect the instructor meant 120 feet, not 220, I hope.

N

 

[lamont]

I clearly never said it was safe. It's all relative, a dive like this can be dangerous, very dangerous, or even foolhardy depending on all of the variables involved.

I have 122 dives over 100 feet but only 10 over 130 feet. My maximum depth of 153 feet was with a pony and a very good buddy with a pony under the ideal conditions I stated above on a site we had dived several times before. We considered the dive relatively dangerous, planned it carefully and executed it according to plan. I'd have to have a very good reason to diver deeper than this and would have to accept the inherent risk prior to planning such a dive.

Good diving, Craig

It is all relative, but these days the risks involved in bounce diving to 200+ on an Al80 on air with little diving experience is definitely so high compared to the options that diving professionals should not be recommending it (which is what started this thread). With the right equipment, gas, training and experience you can do dives to 200 feet, and stay for substantially longer (20+ mins) and get more out of the dive than just being narc'd out of your mind, probably with a larger safety margin than the proverbial average AOW diver on an Al80 diving to 100 feet.

So what is the point of the risk? If the point is just for the diver to exercise their options to accept risk, because they can't stand other people telling them what to do, then they can have at it. There's nothing really to be accomplished by doing that, though, that other divers haven't done much better and safer, so they're not pushing the boundaries of anything other than just risking their life. The calculus in my mind, makes the risks utterly pointless, and I can point to the real-life consequences and the harm that it causes (particularly because its usually not the idiot that does this over and over again who dies, its the naive and ignorant newbie who doesn't have the background to understand the risks that gets brought on one of these stunts who dies). So, I'm definitely not going to agree that the risks are all just relative (strictly objectively, I'll agree they are all just relative -- the universe doesn't care if you kill yourself doing something dumb -- but its the human consequences that matter).

 

[gr8fuldiverNC]

Make sure you let me know which boat you work on so I won't make the mistake of going on that boat. That way it won't be on your record when my luck runs out and I kill myself doing stupid and dangerous dives.[/QUOTE]

my bad on the cousteau bit.

as far as people wanting to do reckless or dangerous dives, that is entirely up the individual. however, when "advanced" divers do these kinds of things while diving with a group of other divers, they endanger others, because now the divemaster is looking at them, and not to others in the group who may actually need the supervision. if there is a problem, then you are endangering the guide who has to rescue you.

'we' (plural) have all done stupid 'dives' (also plural). two people (plural) cannot do the same dive (singular) unless they are on a submarine.

stupid dives dont just start at 131 feet. any dive significantly beyond an individuals training and experience is foolhardy.

 

[IDS_Bill]

Lets, see. My planner software estimates a 1 minute dive to 220ft on air would require 38cf per person assuming 8 minutes of stops and 1cf/min per person on the surface. So it looks like an AL 80 (77cf) is not really enough, and no where near what you should have. Hope for a overfill and don't put air in your BC (I guess that would help you get down to 220.) Then again, don't do it and wait for a set of doubles, trimix, and deco stages along with appropriate training.

I was attempting to read through the 20 pages of posts but finally found what I was hoping for started here.....

Let's do some math to explain M_Bipartitus's correct comment:

At 220fsw - you are at 7.7 atm. If you assume an average SAC rate of .7cuft/min and add in narcosis factor you are looking at about 1cuft/min. Doing the math - 220/60ft per min descent rate = 3.7min at an average of 110 ft = 4.3atm x SAC x time = 16 cuft on the way down. Also remember - at about 175 you go into deco immediately. On the way back up, if you do 30ft per min and have the 30ft stop for 1min, 20ft stop for 2min and 10ft for 3min (cons = 2 in V-Planner), assuming 1 minute at the bottom to figure things out and start getting your a$$ off the bottom, you will use a total of 62cuft of air. Now add in enough air to actually inflate your wing (BCD for you) at that depth and you have used more than your 80cuft tank.

Now imagine something going wrong!

If you have never been to those depths, you have no idea the potentially crippling effects on an inexperienced diver at that level of narcosis.

The instructor wasn't Josh at Scuba Du in Cozumel by chance was it?????

As another answer to your question of 'Is a bounce dive to 220 safe?' The answer is YES - providing you have been trained as a tec diver, have ample gas volume AND RESERVES and are experienced in deep diving. Otherwise you are just weeding out the shallow end of the Gene Pool.......