[Mahler9th]

I have not done all of the reading, but I suspect that any/all or nearly all submersibles that visit the Titanic wreckage are constructed differently, and none feature a composite material.

I doubt any of them can carry more than 1-3 people.

But again, I have not done the reading.

I think read a news story that suggested that there are less than a dozen submersibles in the world that can go that deep. Not a dozen designs, but rather a dozen actual vessels.

If implosion is either confirmed or one of only 2-3 theories supported by research on this tragic accident, it just might be concluded that some element(s) of design, construction and/or maintenance were involved.

Airplanes did not start out as 747s, and now they make airliners with composite fuselages.

It took a while to get to these "achievements" in aviation I reckon.

In any case, thoughts to friends and family members of those that were lost, and thanks to those that tried to help them.