Warning deep "bounce" dives warning

[Frosty]

I guess the point for anyone entering this discussion is to concider the intended audience for thr OP
What seems -and may well be OTT for someome with 300 dives unbder their belt is gonna be on the edge for a newbee diver.

 

[redacted]

So is 10 times depth + 300 aggressive or conservative?

Actually I think it's a mighty fine "rule" Nice way to do multi level dives. If you don't want to surface with 300 psi (understandable!) just do your final ascent from your safety stop with 500 or 600 psi remaining.

I agree, it is not too bad for shallow to intermediate depths depending on what your ascent plan is. I usually plan the end of my dive using my arrival at a 10 to 20 ft rest stop with at least 500 psi in either an AL80 or an HP100. I then work it backwards. From about 80 ft I plan on 750 psi, closer to 900 if I plan much of a stop at 30 ft. Using that rule, you start ascent from 80 ft with 1100 psi which seems on the conservative side diving solo. And maybe a bit aggressive if you are diving with a buddy and actually planning on sharing air and a normal ascent even in an emergency.

 

[dumpsterDiver]

Don't do bounce dives. Follow rules of thumb. Don't do calculations for yourself. Don't dive past 60 feet with a single tank. Don't do short "deep" dives...Is it safer to stay down longer (on a single tank).

Am I getting the picture?

 

[knowone]

TMHeimer, I would say the general answer is to see what it is like doing a quick dive deep without accruing deco, because learning what the effects are to the
individual diver is invaluable, therefore the gas supply was considered in the plan prior to the dive, yet the narcosis pulls you in because under the current Ean regime too little experience is achieved with Martini's Law, which distracts you from monitoring time and monitoring gauges. That results in the slow reaction times and the speedy ascent where the gas runs out before you surface and you may get bent.

Although this mostly happens to any diver having a comfy dive at shallower depths within their training at recreational limits.

The next step is a common thought amongst thinking people, to perhaps look beyond what they have learned in OW, but because courses are so inadequate, with the instructors only regard given to individual competence is "Great, I won't have to keep my eye on her, but I hope he doesn't drown during the course" therefore it becomes an enforced self guided dive most of the time to new divers because a furore errupts when

"O praise the lords for diving literature"






:goingdown:

 

[VooDooGasMan]

You got it right on for this forum.

 

[Teamcasa]

Bouncing is dangerous when you have not been trained, have the right equipment and have planed it properly. That said, so many divers let their ego write a check their ability to handle narcosis can't cash. I know from first hand experience that when I started diving the urge to go deep was overwhelming so a bouncing I went. Fortunately, that day, Lady Luck was stronger than Davey Jones's grip on my stupidity.

I tell all new divers, fight the urge, all the really cool stuff is above 100' anyway.

 

[knowone]

TMHeimer, I would say the general answer is to see what it is like doing a quick dive deep without accruing deco, because learning what the effects are to the
individual diver is invaluable, therefore the gas supply was considered in the plan prior to the dive, yet the narcosis pulls you in because under the current Ean regime too little experience is achieved with Martini's Law, which distracts you from monitoring time and monitoring gauges. That results in the slow reaction times and the speedy ascent where the gas runs out before you surface and you may get bent.

Although this mostly happens to any diver having a comfy dive at shallower depths within their training at recreational limits.

The next step is a common thought amongst thinking people, to perhaps look beyond what they have learned in OW, but because courses are so inadequate, with the instructors only regard given to individual competence is "Great, I won't have to keep my eye on her, but I hope he doesn't drown during the course" therefore it becomes an enforced self guided dive most of the time to new divers because a furore errupts, when an experienced diver tries to impart some valuable knowledge, usually from the same ones that with no facts insist on dissecting an incident having not been there nor likely having been subjected to the circumstances in which any of these incidents may have ocurred, the same ones that don't think, that because they cant do it, it must be dangerous, and suggesting a course will solve the problem

"O praise the lords for diving and divers especially diving literature"


Vale Dr. RW Bill Hamilton

 

[eelnoraa]

So is 10 times depth + 300 aggressive or conservative?

It is definitely not overly conservative. If anything I would say it is I. The aggressive side. At 100ft, you need about 35-40 cf of air to get you & your buddy to surface with all appropriate stops. It may sound like a lot but don't forget, if thing happens, you & your buddy will be under stress, consumption will be higher than usual. 1300psi with Al80 is about 33cf, definitely not conservative at 100ft

 

[Bubbletrubble]

Actually, if I could go back to OW class and wave a magic wand, I would remove some of the emphasis on "don't dive beyond your training" (not because it's not a good message, but because it was mentioned over and over again and is a simple concept), and I would in its place add gas planning (which can be used to good effect on the dives within our OW training).

Here is one gas planning rule of thumb I use in OWD courses:

Don't plan to go deeper than the number of cubic feet of gas on your back.​

And here is one gas management rule of thumb I use in OWD courses:

With a single AL80, it's time to ascend when your tank pressure (in PSI) is current depth times ten, plus 300.​

Both these rules of thumb take into account the need to preserve a portion of "your" backgas for a buddy who runs out. As with all rules of thumb, their derivations are not as important as the ease of remembering and implementing them. And with increasing experience and knowledge one can begin to trade these rules for more detailed and more accurate plans.

In this case, Rules are for fools. Learn and apply proper gas planning and neither rule is needed.

"If you give a man a fish, you feed him for a day. If you teach a man to fish, you feed him for a lifetime." -- Unknown

I'm in the camp advocating that gas planning/management should be taught in basic OW class, thoroughly reviewed in AOW, and refined/discussed extensively in a deep diving course.

I have no idea why a major instructional agency such as PADI doesn't incorporate the teaching of proper gas management into their basic OW and AOW classes. It's just as important as ensuring that scuba equipment is maintained/serviced properly, gear is assembled correctly, all of the appropriate pre-dive checks are performed, and a diver is on the same page with his/her dive buddy (with respect to air-sharing procedures, buddy separation, other emergency procedures, pace of dive, NDL/gas limits, dive profile, communication, etc.).

 

[koozemani]

First, the "bad news." I think it would be a stretch to say that "gas planning" was taught in either of my OW classes. It was drilled in to us to check our SPG's early and often, and to be back at the surface with 500 psi, but as far as how to actually "plan" gas ahead of the dive... I don't remember any real mention of it. If it was there it was not emphasized.

I learned about gas planning here on SB (oh, it exists!), and then from reading further here and on linked pages written by SB members, and then from a one-day class with an instructor that I set up.

+1 on that thought. Five words.