Some details in here that I’m not seeing in much of the coverage:
[1] https://web.archive.org/web/20210804224656/http://www.compositesworld.com/articles/composite-submersibles-under-pressure-in-deep-deep-waters
[2] https://apl.uw.edu/project/projects/oceangate/pdfs/oceangate_script_01.pdf
[3] https://www.businessinsider.com/boeing-university-of-washington-deny-helping-design-oceangate-titan-submersible-2023-6