Re the divers: I wonder if they have brought in anyone with experince diving wrecks or at least caves. In the images of divers I've seen so far they are only diving with one tank. I guess if it failed they could buddy-breath. While lost. In zero viz. In an unstable ship. As they try to untagle each other from debris.

Recreational cave and wreck divers are just plain nuts, but these guys are certainly heroic.