Another fatal record attempt in Lake Garda, Italy

[Celt]

I admire people like Jarek Macedonski for their passion and commitment to undertake a record breaking dive like this. Very sad for his family and friends. These people break the human mould. They do it for the same reason people sail single handed around the world, row across the Atlantic, or walk to the North Pole. Personal challenge.

 

[goldfishtornado]

You could make the argument that these record attempts could be done dry. If the goal is to probe the limits of survivable ambient pressure, just build a powerful enough recompression chamber and dive to whatever depth you want to in a lab.

Sorry, slightly off topic, but this a real thing. As far as I know COMEX has the record at 701 meters equivalent. Apparently is was part of their effort to develop hydrox as a breathing gas.

 

[Degenerate]

I admire people like Jarek Macedonski for their passion and commitment to undertake a record breaking dive like this. Very sad for his family and friends. These people break the human mold. They do it for the same reason people sail single handed around the world, row across the Atlantic, or walk to the North Pole. Personal challenge.

Finally someone who gets it.
Doesn't have to be about ego or "testosterone poisoning" (nice sexism btw, very classy).
Pushing limits has always been a thing for the human race, no matter how little sense those ventures will make to the rest of us.

 

[sea_ledford]

So when you start doing down the first 10m, you’d have to wait for the solenoid to add O2 the mix as the diluent compensate the volume in the loop? I.e. the diluent will bring down the PPO2 very quickly if added to compensate for the loop volume?

There are several ways to skin that cat, and 300m is so far beyond my skill set or interest, I have spent no time even thinking of how to do it, but...
If he had his deep mix plumbed into the unit from the start, he should have brought the PO2 up to setpoint manually during a prebreathe, which would have put him in the 70% nitrox range equivalent. His dil would have been something like 3% O2, so any diluent addition to the loop would have crashed that PO2 pretty quick. I would think he would have had at least one intermediate mix plumbed in though, otherwise maintaining loop volume and PO2 would be a significant task load.

It's certainly possible that he got task loaded shallow, the ADV fired too many times in order to maintain loop volume, and whatever diluent he had wasn't rich enough in O2 to maintain consciousness.

But if the O2 bottle is turned off, once the O2 in the loop is metabolized you go to sleep, doesn't matter what the dil is.

 

[Vicko]

The gear used for training dives before covid lockdowns did not have additional diluents. They had a 6l of dill, 3l of o2 and 6l of inflation gass backmounted.
That was all the gasses taken for 200 or so meter dives.
It was decided that carrying bailouts would result in overbreathing the scrubber anyway, and as the dives were done in open water and they kept loosing guidelines no deposits were made.

 

[Wibble]

The gear used for training dives before covid lockdowns did not have additional diluents. They had a 6l of dill, 3l of o2 and 6l of inflation gass backmounted.
That was all the gasses taken for 200 or so meter dives.
It was decided that carrying bailouts would result in overbreathing the scrubber anyway, and as the dives were done in open water and they kept loosing guidelines no deposits were made.

What, doing that record breaking attempt without bailout and support divers?

Not even bailout AND decompression rebreathers?

That depth would be 10 plus hours of decompression, well over a rebreather's CO2 scrubber lifetime. Even if he planned a few seconds on the bottom— to take a selfie "look at meeee" — any delay would add hours of additional decompression.

Seems more like a successful suicide attempt.

 

[Wibble]

Threw 300m/1000ft into MultiDeco for a larf.

10mins (giving 2mins on the bottom) with 3/90 gas and 1.1 set point.
Over 11 hours of decompression.
Oxygen toxicity is an issue: CNS near 300% and OTU's of 800

Any dive to that depth has an extreme level of planning with extremely esoteric techniques, such as variable set points and many diluent gas changes.

Bailout planning is even harder, relying on a team support divers running a complex and very detailed plan.

 

[Wibble]

Curiosity and a cat…. Couldn’t resist playing around with the plan.

• 300m/1000ft for 10mins (which assumes 8mins to descend, 2mins on the bottom) using 3/90 gas at set point 1.1
• 120m/400ft switch to 9/65 gas and set point 1.3
• 21m/70ft switch to 21% (air) and set point 1.2

Yields an 8 hour dive that's going to play havoc with your lungs with around 210% CNS and 600 OTU's — you’d talk like someone who smokes 60 a day

Again, the smallest increase in bottom or v.deep time will massively increase the decompression time — roughly an extra hour of deco for every extra minute!

At least two rebreathers required for that runtime plus whatever the bailout strategy needs.

 

[Trace Malinowski]

It's interesting to me that it's okay to sanction world records for hot dog eating promoting death by cholesterol, but deep diving is forbidden.

 

[Wibble]

It's interesting to me that it's okay to sanction world records for hot dog eating promoting death by cholesterol, but deep diving is forbidden.

It does harm the reputation of our "extreme" sport. Most people know what happens when you eat your own weight in chillis 🌶. Most people think that scuba is dangerous and all deaths affect the public's attitude, confirming how dangerous it is in their minds.