“Cameron, who is considered an expert at diving and submersibles...”
In much the same way that Alex Baldwin is an ‘expert’ on firearms?
*SNORT*
Actually James Cameron built his own sub and is one of the few people who has gone down into the Marianas Trench.
He is a liberal Hollywood director, but in this case Cameron knows what he is talking about.
Normally I’d agree with you on a Hollywood figure, but Cameron is *actually* an expert - not a leading expert, but he’s got engineering and crew experience on submersibles. Here’s one of the craft he worked on: https://en.wikipedia.org/wiki/Deepsea_Challenger
He got into diving and submersibles in order to advance his filming. One of those “In order to advance my career in one field, I had to become an expert in another” or “I took up a hobby and became an expert in that field” kind of things - kind of like how Paul Newman was an actual expert on motor racing, for example.