I was talking about the bathyscaphe for going into the trench.
But Branson, Cameron, and whomever else are trying to do is something more than the bathyscaphe. They’d actually like to go into the trench and be able to do a tour of it.
A steerable submersible of some kind.
Exactly what do you think the bathyscaphe was, if not a steerable submersible? It was not connected to a surface ship, carried it's own power for steerable thrusters, and dive time was limited only by battery power and crew endurance. After a crack developed 5 hours into the dive they continued to the bottom, took pictures, and returned safely to the surface.
Regards,
GtG
PS They reported seeing fish at the bottom of the trench!