Vessel Divers Searching Sunk Superyacht- Sicily

[Searcaigh]

To be clear, at the time of posting this I do not have even 50 dives in my logs, and am not Nitrox certified. And even still, even still, with my limited experience, when I saw a photo of what I now know to be a member of the Italian Fire Brigade entering the water with a single 15L air tank, my first thoughts were "Why aren't they using nitrox for that depth? Surely they must be using nitrox. Maybe they label the tanks differently in Italy?" Such a fool am I...

They're using 21% Nitrox

Highest percentage for a 50m dive would be 23% at a PO2 of 1.4 so makes no difference and as @Angelo Farina mentioned they are doing deco on the ascent.

As we are not privy to the actual practice of this team doing the recovery, we can only assume certain aspects of how they are managing this situation.

 

[Wibble]

I'd much rather be rescued by a first responder diver with a single 15 litre containing air than be recovered by a trimix rebreather cave diver days later.

 

[Angelo Farina]

+ And even still, even still, with my limited experience, when I saw a photo of what I now know to be a member of the Italian Fire Brigade entering the water with a single 15L air tank, my first thoughts were "Why aren't they using nitrox for that depth? Surely they must be using nitrox. Maybe they label the tanks differently in Italy?" Such a fool am I...

Nitrox is way overrated. Here in the Med, we consider it useful only for a limited range of depths (say 25 to 35 meters, which is NOT our favourite depth range, the best is either shallower or deeper) and when doing repetitive dives in a day. Which, again, is not so common: we often prefer a single deep and good dive in the morning, seeing red coral, lobsters, paramuricee, and the other things you only find below 45m-50m, followed by a good lunch at the restaurant, and spending the afternoon doing other water sports or simply relaxing...
I never understood people doing 4 dives per day, shallower and shallower, because they fear anxiously to have to do any deco stops...
So Nitrox is not widely employed here, as instead it appears to be in the Caribbean area. I am NOT Nitrox certified, albeit I am certified for CC recreational rebreathers... I can even use pure oxygen!
I am not tech certified, either...
I fully understand how this can sound strange for people used to different systems, and diving in different environments.

Speaking only for myself, thank you @Angelo Farina first of all for what appears by my count to be nearly 40 years of willingness to serve as a firefighter - something that fewer and fewer people are willing to do these days, at least in many parts of North America, given the difficulty and risk level of the job and the incredibly poor remuneration (in terms of salary and benefits, that is). And for seemingly some part of those years - well, it takes a special kind of diver to be willing to use your diving skills for body recovery work, regardless of the conditions... so, simply, thank you.

Well, I was in real service as firefighter just for one year, in 1984, plus two short periods of one month each during a couple of emergencies (a big snow fall and an earthquake).
For the other 40 years, I remained in a quiescent state, ready to be recalled, but not in service. For many of these years (the first 15) I was indeed also an expert in body recovery in the Civil Protection, being an active member of the local diving club, Parma Sub.
And I had to conduct several body recovery operations (a dozen, more or less), and more than 20 reharsals - test operations. During one of the real operations I was the diver effectively finding and recovering the dead body in a river (a 7-years old child, really a sad story).
But, as explained, volunteers operate very differently in Civil Protection than professional firefighters.
Then I had sons, the work demanded more time, so I retired as body recovery expert for muddy rivers.
Only in 2007 I returned in the Civil Protection as a volunteer, but now with a very different expertise: I had two Golden retrievers, I trained them for search of trekkers lost on the mountains, with the specialty of conducting the dogs from a motorbike (actually a Vintage Fantic Trial). This activity was organised by a motorbikers club (Motoclub Crociati Parma).
The specialty of motorbike + research dogs is quite unique in Italy: we were only 4 volunteers with this specialty. This allows to cover a much wider area in shorter time, and, under favourable conditions, to carry the lost person back to a recovery point, as our vintage trial bikes are equipped with a long and comfortable seat and are homologated for driver+passenger (standard trial bikes have no seat and are driver-only).
Here you see my collection of vintage Fantic Motor trial bikes:

Fantic Motor Photo Gallery

My collection of Fantic Motor bikes

www.angelofarina.it

And here you see my Golden Retrievers Argo and Penny (now defunct, unfortunately):

Argo & Penny home page

Golden Retrievers of Angelo Farina

www.angelofarina.it

Sorry for having derailed this thread to my personal experiences, which are completely OT.
But this is Scubaboard, I see that these derailings are quite common, and moderators tolerate them...
I love Scubaboard also for this!

 

[pauldw]

It's good to hear Angelo weigh in. And I do respect Italy's pioneering work in diving, even though the early work was to make mischief.

That said, there's a documentary on Hulu right now called "Gone in 16 Minutes: Sinking of the Superyacht," that claims that there were people in air pockets who didn't drown, but lived until they ran out of good air. I don't know whether that's true, and if it is true, I don't know but what they may have died before divers got down there. No one says anything about any tapping on the hull from people inside still alive. But that bit of possibly true information about air pockets raises a couple of questions in my mind. If, as the documentary claims, bottom time for the initial dives was twelve minutes, what exactly could be accomplished down there in such short time frames? There was mention of failed efforts to cut holes in the hull, but wouldn't that just kill anyone alive in there, when water started flowing in through the cut? And it seems like it would require power tools anyway. Ultimately, it seems like the purpose of quick, short dives would be a quick recon to hope and search for evidence of life (like tapping sounds). But if there was such evidence, wouldn't it then be necessary to send down people who could stay down, and work their way through the passageways? What would that require, rebreathers?

"Gone is 16 minutes?" Maybe. Reminds me of that movie, "Gone in 60 Seconds."

 

[Searcaigh]

that claims that there were people in air pockets who didn't drown, but lived until they ran out of good air.

This is information that I heard too on the e-Sysman channel on YouTube.

Several people, including the owner, had been found in one area and the owner's daughter was trapped in her own cabin.

 

[DandyDon]

"Gone in 16 Minutes: Sinking of the Superyacht," that claims that there were people in air pockets who didn't drown, but lived until they ran out of good air.

This is information that I heard too on the e-Sysman channel on YouTube.

Unverified rumors like those are common with disasters, and they get repeated enough that some may believe them. You just never know how much truth may be involved.

 

[Still Kicking]

Great article in the NYT on this incident (it doesn't get into the dive aspects but brief video shows recovery divers using surface-supplied air). Not sure if this link will get you over the paywall but if it does, it's worth the read.

What Sank the Tech Tycoon’s ‘Unsinkable’ Yacht?

A Times investigation has found that an unusually tall mast, and the design changes it required, made a superyacht owned by a British tech mogul vulnerable to capsizing.

www.nytimes.com

 

[Wibble]

Just a point about air pockets at 50m/165ft…

The pressure there is 6 atmospheres, so a large air pocket is shrunk to a small one sixth of the volume. Also on the descent, the yacht turned sideways, probably pouring the air bubbles out of the spaces. Needless to say there would be no light as electrical systems would fail underwater.

Not nice for the casualties. Unlikely they would have survived beyond the initial sinking.

 

[Vicko]

Air pockets are common in ships that sink quickly, the thing is just because it's an air pocket does not mean it's permanently breathable. Most people think of whole rooms being filled with air, in reality it's tiny corners where a person succumbs to hypoxia or co2 rather quickly. Even if they survive for some time the deco obligation at 50m becomes a problem if there isn't a diving bell and saturation chamber available for rescue.

Example like these are rare.

 

[Jared0425]

Air pockets are common in ships that sink quickly, the thing is just because it's an air pocket does not mean it's permanently breathable. Most people think of whole rooms being filled with air, in reality it's tiny corners where a person succumbs to hypoxia or co2 rather quickly. Even if they survive for some time the deco obligation at 50m becomes a problem if there isn't a diving bell and saturation chamber available for rescue.

Example like these are rare.

The tug landed upside down and in 90ft of water. The whole compartment was empty and was slowly filling up. As of now, that is the only deep water case ever to have happened.