Didn't wanna chip in on this but here I am now
The Americans not accepting help from certain companies is mental, reminds me a lot of the Kursk incident where the Russian denied everything until it was way too late and it was perfectly feasible to rescue them.
There are a few bad takes on this thread, so as someone who works in the industry, let me address them:
1. People saying it is simple and blah blah, simple is good in these sort of vehicles, less things to go wrong.
2. The controller is common in DSV/UROV's and even Submarines, I have seen PS4 controllers used and XBOX ones also, same as USAF use for their drones. It is a simple, mass produced set of switches which is intuitive, it makes a lot of sense and you can have lots of spares.
3. The safety systems. There seemingly are none, this is the main flaw for me, it's proper amateur hour, the main thing is the lack of cameras on arms, you need a 3rd person view of your surroundings to properly navigate them, using one or two close to body cameras is super dangerous in a ROV let alone a DSV with crew.
I would hypothesise that they are stuck under something, why? Well the DSV will have water fuses, if it remains in water for too long, they pop, drop the ballasts and deploy the balloon to bring it to the surface safely and automatically. Clearly that has not happened so I would say it must be stuck under wreckage they got too close to or something otherwise the fuses failed or whatever but it is simple tried and tested tech... very odd!!
I remember Robert Ballard in his Titanic book talking about the one golden rule of piloting a submersible: never go under an overhang, especially a man made one.
I don't know much about submersibles, but I know a fair bit about the Titanic, and the wreck. The only places where a DSV could get caught like this is either the bow or stern. It may be caught under the overhang of the stern by the rudder and propellers, or perhaps landed on the ship by the grand staircase at the bow, but misjudged the ballast, causing the roof to collapse and for the sub to fall into the bowels of the ship.
I would imagine DSVs would descend to the wreck site safely away either bow or stern, and then be guided to them. Perhaps once they were there, the pilot decided to show off to their prospective client at the wreck site, and took a stupid risk?
And one other thing, major malfunctions on DSV's aren't unheard of. During Alvin's visit to the wreck site back in 1986, the sub's onboard sonar went offline more than once, and at least twice seawater got into the batteries and started a short, causing the dives to be cut short. They still made it to the bottom, but could only stay briefly.
That's on a sub considered top of the line for it's kind of work, with all the expertise, engineering and money the US Navy cared to put its way. I doubt this private company has anything like those resources.
