retitive bounce diving

[Jim Cruise]

I would be pleased to receive any advice on the following:

We are undertaking inspections down a fixed line for a short duration of time e.g. down from surface to bottom 16m, 2-4 minutes on bottom, then slow ascent to surface. Swim or be towed 50-80m start next inspection dive.

May do 4 or 6 dives in succession, treating them as 1 dive (surface interval less than 15 minutes) for DCIEM table calculations.

Diver may do 3-5 days as a part of a 4 person team, but does multiple days of this work.

What are dangers of this multi-ascent single dive, plus the multi-day workload ?

 

[Diver0001]

I would be pleased to receive any advice on the following:

We are undertaking inspections down a fixed line for a short duration of time e.g. down from surface to bottom 16m, 2-4 minutes on bottom, then slow ascent to surface. Swim or be towed 50-80m start next inspection dive.

May do 4 or 6 dives in succession, treating them as 1 dive (surface interval less than 15 minutes) for DCIEM table calculations.

Diver may do 3-5 days as a part of a 4 person team, but does multiple days of this work.

What are dangers of this multi-ascent single dive, plus the multi-day workload ?

Why do you need to return to the surface between each leg?

R..

 

[Dr Deco]

Hello Jim:

I have heard of divers performing dives such as this when searching for shellfish in the Pacific Northwest. Apparently this is regularly done and the divers do not suffer any untoward effects. It surprised me when I first heard about it but apparently it works.

Dr Deco :doctor:

 

[H2Andy]

i would imagine that the minimal time at depth would prevent any significant intake of
nitrogen (or any inert gas you might be using) into your system, thus
reducing the risks usually associated with reverse profiles or bounce diving.

however, i think i would keep the "total dive time" low per day, not going anywhere near NDLs ... maybe even halving them, if i at all could...

so at 50 feet that is 80 minutes NDL (PADI), so let's
say keep it to 40 mins max. he's talking 6 dives at 4 minutes each max... that's 24 minutes... so... yeah... nice margin there

also, i would avoid swimming or any excercise. let them tow you and do as little as you can while on the surface and afterwards...

anyone, am i missing anything that could be helpful?

 

[Otter]

and EAN 40% ???

 

[H2Andy]

oh good point...

yeah... he's diving to about 50 feet, so a nice and high EAN mix would help a lot

 

[pipedope]

Lots of jobs require a drop to depth, do some task that takes a very short time, surface, wait while something else gets done, do back down do another short task, lather rinse repeat.

Diving to 52 FSW (16 MSW) won't load you up very fast but it will add up over several dives.

I would make the first dive with a fairly quick ascent, 30 FPM (10 MPM) with only a 1 minute stop at 15 FSW (4-5 MSW).
I would add to the safety stop time with each dive and add a stop at 1/2 max depth on the last dive.

I would also do a 5 minute neurological exam after the last dive and again an hour later just to be on the safe side.

I have done as many as 10 dives like this in a day but I also had a chamber on site.