Reducing DCI risk by staying immersed on surface after a dive

[34109411]

Filthy casuals. /s

I love the last (free) 5 minutes of the dive, while everyone is crowded around the dive ladder and fighting to get to all the stuff you listed I'm having a protracted safety stop and watching all the critters that are floating around.
Boat crews hate me.

lol
like me

 

[Dsix36]

According to doppler bubble studies done by Dr. Neal Pollock a few years back on a liveaboard, the divers bodies were bubbling more at about 10-15 minutes after exiting the water than when they first exited. I was not any type of proven test for DCS but it leads me to think that exercise right away is better than waiting a few minutes when I would be bubbling more, BUT does that exercise cause more bubbling. More studies still need to be done for any type of definite answers.

 

[boulderjohn]

According to doppler bubble studies done by Dr. Neal Pollock a few years back on a liveaboard, the divers bodies were bubbling more at about 10-15 minutes after exiting the water than when they first exited. I was not any type of proven test for DCS but it leads me to think that exercise right away is better than waiting a few minutes when I would be bubbling more, BUT does that exercise cause more bubbling. More studies still need to be done for any type of definite answers.

Do you have a link to this, Don?

I have not seen that study, but I did see the results of a similar study done by Mark Powell in Europe. He was comparing divers using different deep stop depths on decompression dives. IIRC, he tested them over time, and he found the ones using the shallower first stops had a steady decrease in bubbling over time, but the deeper stop people did have an increase over time. That study was not published, so I can't link to it.

 

[dmaziuk]

How much exercise is "exercise", I wonder? Climbing the ladder and taking a few steps in gear is hard work after you've been weightless for a while, but it only lasts what, 30 seconds?

 

[lowwall]

You can probably reduce risk by three simple practices:
1) Pay attention to your dive computer and don't run your NDL to zero
2) Make a slow assent to your safety stop at 15 feet
3) Extend your time on the 15-foot safety stop to 5 minutes whenever possible

4) make as slow an ascent from the safety stop to the surface as possible
5) if you are on Nitrox, keep breathing it until you sitting down on the boat

4 is more important than 5

 

[happy-diver]

It suggests people are ridiculous

Totally not getting the analogy here.

That much being said I'll suggest why people might want to return to the boat sooner rather than later at the conclusion of a dive.

1- They're cold
2- They're hungry and thinking about their lunch in the cooler or the snacks given out by the dive charter
3- They're thirsty after breathing dry compressed air for what might be the better part of an hour
4- They want to get out of their gear and out of (or mostly out of) their dive skins (if there's going to be a subsequent dive).
5- They want to get their gear stowed before the boat fills up so they can find an out of the way place to relax which brings me to 6
6- They want to grab a good spot on the bow or the upper level sun deck

and after weeks and days of effort to be underwater, they have the rest of the day for land people things
some rewiring tighening nuts and even soldering can accommodate these failings and even extend dives

 

[RVBldr]

How much exercise is "exercise", I wonder? Climbing the ladder and taking a few steps in gear is hard work after you've been weightless for a while, but it only lasts what, 30 seconds?

It's just not "exercise" as such, but just the act of straining can aggravate a shunt if you happen to have one, and with a sizable % of the population with PFOs or an AVM, most don't know they have one. So if you're bubbly, just that straining is potentially enough to shunt enough bubbles to give you some problems.

 

[Doc Harry]

As far as DCS is concerned:

It's all about the pressure of the gas you are BREATHING.

NOT the pressure on your body.

 

[tursiops]

As far as DCS is concerned:

It's all about the pressure of the gas you are BREATHING.

NOT the pressure on your body.

Isn't the gas you are breathing at ambient pressure? And isn't your body also at ambient pressure? And isn't the offgassing about the pressure gradient between the greater-than-ambient-pressure gas dissolved in your body versus the pressure in the gas you are breathing, i.e. at ambient pressure?

 

[dmaziuk]

As far as DCS is concerned:

It's all about the pressure of the gas you are BREATHING.

NOT the pressure on your body.

Right, except for the part where, thanks to our physiology, the pressure of the gas you're breathing need to be within .15-ish of the pressure on your body, and thus the two can be used more or less interchangeably for practical purposes.