Inwater Recompression Experiences

[Michael Guerrero]

Please post your experience with inwater recompression. Please include the means you used (e.g., full face mask, surface supplied or backgas, comms, tender, etc.), overall assessment of the outcome(s), and likelihood of doing it again.

Thanks.

 

[oldschoolto]

Never had to do it... But, needed to use the bottle on the down line to get done with my DECO obligation...

Jim..

 

[100days-a-year]

DISCLAIMER DO NOT TAKE THIS AS A SUGGESTION

Have seen it used to "unbend"multiple divers and seen some return to diving within 2 hours.Do not try that as it is ridiculously high risk.
AL80 with 100% 02 and a normal reg.
With or without a safety diver in the water.

We are often 6 to 24 hours away from a chamber and working UW.IWR is our safest and most viable option.

 

[Patoux01]

@Kevrumbo had some "fun" with it, I believe.

 

[Kevrumbo]

In-Water Recompression, Revisited

 

[Michael Guerrero]

Thanks Kev.

So 100-Days, was that for mild type I symptoms? Kev's experiences, as identified in the linked post, were of mild shoulder pain.

It seems appropriate that you could treat those types of symptoms with a dip back in the water following one of the published IWR profiles. For something more severe though, I think I'd be reluctant to not have a full face mask and someone keeping an eye on me.

Also, if you follow the Navy IWR profile, it's 60 minutes at 30', 20', and 10'. No air breaks, and 2ft/min ascent. OR, it's 90min, 45min, 45min at the same depths for a Type II hit.

Either one of those is going to take more than one AL80 of O2. So, if you are going to do this with OC gear and will need to switch tanks, do you employ a gas switch block, quick disconnects, some combination of the two?

 

[cathal]

On a couple of dives either at or near the surface, I experienced twitches or mild discomfort in shoulder region. I returned to the 6m bar and did an extra 20 minutes or so. Resurfaced with no symptoms. Water temps were 13-14c in open ocean. Conversely on a couple of dives I have stayed an extra 40 minutes unplanned or so at 3m to accompany a diver on their last stop. After each of these dives I have felt really great

 

[Akimbo]

I would add an air-bailout bottle manifolded into a FFM if I were gearing up for IWR. That would allow an attending diver to quickly get the patient off O2 in case of convulsion and would make air-breaks easy. I would also make provisions for treating two divers. The idea is to treat both if one gets hit. You have to be very conservative if chambers are far enough away to justify IWR.

A large cherry buoy on the hang-off line between the diver and boat is also a good idea in case the seas aren't flat. You don't want to add physical stress by jerking divers with every swell. I would also include a hydration bag with a short hose in the kit.

IWR was always an option on commercial surface dives in the event of a chamber failure... extremely remote but possible. Preparation was no big deal since we were already on an umbilical, FFM or hat with comms, and had plenty of O2 onboard.

 

[Kevrumbo]

. . .So, if you are going to do this with OC gear and will need to switch tanks, do you employ a gas switch block, quick disconnects, some combination of the two?

A bare economic minimum "semi-FFM IWR" set-up if you're breathing oxygen only is the OTS Mouth Mask w/ gag strap (model HM2B, $85 USD):

Use switch blocks and/or QC6 plug-ins if you're going to utilize Air Breaks (or quickly switch to Air if signs of OxTox/convulsions). Or less convenient and more risky Open Circuit option, use two mouth masks -one for O2 and the other for Air- and physically swap/remove & replace between the two. . .

 

[Akimbo]

A bare economic minimum "semi-FFM IWR" set-up if you're breathing oxygen only is the OTS Mouth Mask w/ gag strap (model HM2B, $85 USD):...

I wouldn’t want to be a patient or tending someone convulsing while wearing a mouth-mask. Besides, comms is really bad compared to a FFM. IWR isn’t a trivial matter and saving $300 over a FFM isn't much if you plan to do it right... with comms, umbilical, etc.

You're basically talking about expedition dives to be that far from a chamber AND responsible for IWR prep. A liveabaord operating that far from a barrel should have an IWR kit onboard and the crew to manage it.