This seems like a real-life Clive Cussler novel.

On a serious note though, I really hope this ends with good news. In absolute blackness and the pressure of 13,000’ of water is not a good way to go. Fingers crossed that the pressure vessel has maintained integrity and the rescuers find it before the oxygen runs out.

Frankly, I'd rather implosion and nigh instant death. If they can't open the hatch, suffocation is the end point. Add to this they likely have no or little food and water, so those could come first.

Anything that extends the time you live makes you ask an obvious question: Do we kill people to extend the time for the others? I hope to never go through that, and hope they didn't have to either.

My condolences to their families.

Will become a tourist attraction themselves alongside the Titanic for future ghouls.

And they can make a movie about it.

it's wrecks all the way down

I wonder if some kind of sonar transponder with an independent power source is possible under 2 miles of water. A beacon signal to home in on.

If ultra short base line position was lost, then it would be a back up system.

Aircraft black boxes are capable of handling those sort of depths, and they have a sonar transponder that will generate a "ping" for about a month (on a full battery charge). Developing something like that to for a submersible is should be possible, and should be mandated for submersibles being used to carry tourists. It would also give an independent way of continuously tracking the position of the submersible relative to its mother-ship.

Developing something like that to for a submersible is should be possible, and should be mandated for submersibles being used to carry tourists. It would also give an independent way of continuously tracking the position of the submersible relative to its mother-ship.

I rather hope that becomes mandatory as well. AFAIK miltary submarines can deploy rescue beacons, but obviously don't operate at these depths. Being unable to reliably track the vessel seems like a serious oversight, regardless of the technical difficulties of doing this.

but might be mostly academic. As one of the other posters pointed out, there are only a handful of subs or ROVs that could reach those depths, and none that could rescue someone if they could reach it. So while there are layers of additional tech that could be developed, at a certain point you cross into cowboy country and choose to risk a one way trip. This is a discipline as demanding as space travel, but with a fraction of the budget, and every sub that can hit those depths is essentially bespoke.

While I can understand the hope some hold on to, the odds are not in their favor, and put it frankly running out of air would be one of the the worst ways to go. It is likely that with the prompt loss of communication and time from surface contact that the sub imploded. While the location of the subs wreck may provide closure, it is unlikely to have a happy ending. So while additional communications or telemetry channels might have provided more clarity, they would be unlikely to change the outcome.

...and given that it is around 36 hours left (approx at time of post) the other question is if there was anything capable of helping, is it anywhere near - if you have to factor in significant travel time before you even start anything it looks iffy. It may be academic if there is nothing capable.

I wonder if the limit isn't oxygen but carbon dioxide - don't know how much scrubbing they have available :(

At this point they're either on the surface somewhere without power, they're dead or about to be.

Oceanic depths are in many ways more challenging than space - at least in space you only need to deal with one atmosphere of pressure.

Sure you can. Indeed, it's been done. The problem is, in every previous case the beacon marked the place where the wreck was found... if the beacon survived the event that caused the wreck. Imploding at 3800 metres down will cause dieseling, where the imploding air causes everything in its path (which is everything inside the sub) to catch fire. Briefly. Until the water arrives to put the fire out. Very few things can withstand the dieseling followed by extreme pressures. Aircraft transponders will work even at extreme depths, but that's because the pressure gradually builds on the way down. Aircraft are designed o keep air pressure in, not water pressure out, and won't go very deep before cracking and letting water in, at which point pressure inside and out is equal and builds slowly as the aircraft sinks. They were already at depth, two hours out of 2.75 hours to target, when the signal was lost. If the thing imploded, there will be pieces of sub scattered over a wide area. USS Thresher, lost in a lot shallower water (2600 metres, not 3800) was scattered over 130,000 square metres. There will be fewer big pieces and lots of little pieces (No nuclear reactor or steam turbines). Don't even bother looking for bodies, the dieseling will have effectively vaporised them.

Jerry-rigged appearing stuff isn't comforting...however, facing 6000-ish psi (400-ish bar), I imagine that everything important was thoroughly FEA-ed.

You would like to think that the scenario where an emergency surfacing event was considered (probably some way from the support ship) and some independent means of locating the vessel on the surface would have been considered as a mitigating measure as part of the design risk assessments, over and above the sonar comms.

Sadly, as there is no mention at this time of this facility being fitted or operating, it doesn't bode well for the outcome.

this is where the bit about the vessel not being regulated/registered/approved becomes important.

"this is where the bit about the vessel not being regulated/registered/approved becomes important."

But is it though?

What organisation would regulate/register/approve? When something is inherently high risk and of no particular strategic value to a nation state, which public / governmental body would stick it's head above the parapet and say 'yeah, this is safe'?

Besides, the company themselves are unlikely to be absolute idiots. They are going to risk assess and mitigate risks as best they can to ensure their business has a future.

Finally, the potential clients paying top dollar are not likely to be fools and more than likely do some kind of due diligence regarding mitigation of risks. The notion that self made wealthy people are just lucky is a fallacy, they have above average intelligence and like taking risks but not unacceptable risks.

Frankly, the personal opinion on 'jury rigged' I give very little credence to without more detail. The fact that the ballast may have been repurposed from another use is immaterial, its still ballast.

> Besides, the company themselves are unlikely to be absolute idiots. They are going to risk assess and mitigate risks as best they can to ensure their business has a future.

Not to mention -- their CEO was onboard. That has to be interpreted as a strong vote of confidence on his part; you'd think he would know if the craft was dodgy.

& make a big thing about control via a Bluetooth video game controller.

I have this feeling that something mindboggling stupid happened like no spare batteries\depleted charge or something happened to the Bluetooth video game controller, they left without a spare & thus have no means to control the sub.

I'm hoping for a positive outcome, but frankly I don't see one coming.

Even if the sub hasn't imploded, which it probably has, the nearest rescue subs would be the American Deep Submergence Rescue Vehicle assigned to the Atlantic... except that both American DSRVs have been decommissioned and replaced by underwater drones, and this thing is likely 2 miles (3 kilometres) down, where the American DSRVs were designed to rescue from 600 metres and had a never-exceed depth of 1.5 km.

Note that the drone has a design depth of 610 metres. That's not happening.

The American DSRVs, now no longer with us, were about as good as anyone else's DSRVs, and a lot closer than most. Mystic, the Atlantic DSRV, could have been on site in under 24 hours, possibly under 18 hours. But it's gone. And even if it were available, there's the problem of finding the sub. DSRVs are not speed demons and don't have the best search equipment, there just isn't space. Even if Mystic was available, it is extremely unlikely that the sub would be found in time.

You go deep, you go alone, lads and lassies.

a worse fate....

But I thought these things had their dive weights clamped on by electromagnets... sub loses all power, the dive weights fall off and the sub rises to the surface... although could lead to an even worse fate given the crew hatch is bolted from the outside(according to BBC) so they could bobbing on the surface and still run out of oxygen..

The notion that self made wealthy people have above average intelligence is itself a fallacy, perhaps even bigger than the one you just pulled out your backside.

Only an idiot would get into any vehicle or building that by design cannot be opened from the inside. The obvious question to ask is how do I get out if this thingie floods or catches fire? And for this particular case the obvious followup is how do I get out if the sub runs out of breathable air? That's nothing approximating to due diligence. It's just basic common sense.

Maybe the poor sods who are in this submarine did ask those questions. Maybe they didn't. Barring some miracle, we'll probably never know. If they did ask those questions, they presumably decided it was still worth the risk. I hope they are proved right but fear they won't.

A lot of early spacecraft had hatches that were bolted down. Famously the Mercury capsules had explosive bolts to allow emergency escape. On at least one occasion the explosive bolts exploded when they weren’t supposed to. Oops.

Only an idiot would get into any vehicle or building that by design cannot be opened from the inside.

So you know more about designing a door to survive 400 bar pressure?

Very likely this claustrophobic aspect was out of engineering necessity, not carelessness.

... because he demanded an independent inspection of the craft to ensure safety.

"Lochridge, whose role included overseeing safety on the Titan project, had urged OceanGate to seek classification several years ago, before he was sacked in a disagreement about safety checks on the craft."

I wonder if he was inspired by any other more famous submarine-inventor CEOs who have a penchant for firing anyone who shows a shred of caution about taking big risks?