Bounce dives

[BobK]

How many here have done 5 or more bounce dives in 80+ FSW in a day ? And, if so, did you, or someone who was diving with you have any DCS incidents ? A thread on a different board had a discussion about this and many of the participants feel that bounce diving is risky diving. I wanted to get some antecdotal evidence one way or the other.

Thanks

[Marcus]

Excuse my ignorance but why would bounce diving be a problem? So long as you follow correct ascent rates, I don't see an issue with this. Assuming a dive computer is being used.

[diligaf]

Originally posted by Marcus
Excuse my ignorance but why would bounce diving be a problem? So long as you follow correct ascent rates, I don't see an issue with this. Assuming a dive computer is being used.

Different types of dives create different types of problems… and bounce diving certainly has risks, especially if a problem occurs in an earlier dive.

One of the most common mistakes is to rely on your computer… it should simply be used as a guideline, especially when bounce diving. Always make a safety stop, whether you have a deco obligation or not and add a little extra time (on your safety stop) with each dive.

Many years ago a dive buddy of mine had an embolism after doing a bounce dive. Fortunately, we were prepared and were able to save his life. His mistake… he followed his computer and surfaced without making a proper safety stop.

[fishhunta]

i voted that i have felt kinda funny at the end of the day. but that is only after a lot of dives, probably more than 5.
i also feel funny after multiple extended deep dives even when following the navy tables, but most of those days started off with a 200ft air dive, so i guess i could expect to feel funny.......

[ROCK BOTTOM]

I know that I was pushing it a bit, but I have done two drops to 180, two to 165 and one to 110 fsw, then followed it up with a tank draining dive in 45 fsw to end the day. I was exhausted but only due to the level of exertion swimming in a current and fighting the fish.

Zz

[FredT]

That is with up to 17 dives a day.

I just spent 2 weeks working underwater, generally with 8 or more dives a day with depths varying between 10" and 147'.

That many entries and exits alone whups most folks (me included) but the DCS issue didn't come up. I did need to do some deck deco on O2 the last day to set up for the last equipment retrieval dive since I was pushing the edges of the puter a bit late in the day.

[Chad Carney]

Bounce dives are the norm for most west coast shooters, because our stuff is so spread out.
But they can be done with extra safety margins imposed, like good stops, ascent rates and rich EAN scrubbing. Computers are the best way to measure nitrogen uptake on a dive, but they should never be pushed to the edge, and use back ups.

Exertion is a huge factor, especially on repetitive dives.

Chad

[Spearo_Fla]

Let me think I've done at least 30-50 bounce dives to 80 ft in a day. I've never had any ill effects. Oh wait a minute, I don't use tanks! Duh;)

[BobK]

Originally posted by Spearo_Fla
Let me think I've done at least 30-50 bounce dives to 80 ft in a day. I've never had any ill effects. Oh wait a minute, I don't use tanks! Duh;)

That doesn't guarantee you won't get a DCS hit. Some freedivers have. You're total BT during the day can get pretty large.

[WonderBoy]

Pardon my ignorance, but how does a freediver accumulate bottom time when he/she is not breathing compressed air at depth?

[FredT]

Originally posted by WonderBoy
Pardon my ignorance, but how does a freediver accumulate bottom time when he/she is not breathing compressed air at depth?

Bottom time = amount of time spent between starting decent and starting ascent.

Note also that freedivers do not as a rule ascend at 20-30 ft/min. This tends to accelerate formation of microbubbles.

Freedivers have been bent!


FT

[BobK]

Thanks for the data !

[Stodelle]

As a rescue diver in SoCal, I spent some time with with Carl Huggins at the Catalina Chamber. Believe it or not, he said that he treats a high number of Freedivers. It has to do with the ascent/descent rates.

I have done bounce dives at altitude (7000') to 150' and our team leader always had us put on o2 afterwards just for safe keeping. We had several neuro's done on us and between the slight narc in the dive, and the o2 on land. I always felt good.

**Please note that I am in no way saying this is good, safe, etc. This was during law enforcement rescue work where we did not have time to wait for specialty gases. I say this to avoid all the "you dum @$$" comments this would surely start. It just goes along with the poll and thread which is why I am offering my observations.