i guess the difference was that ocean gate needed to recoup the expense and make a profit as fast as possible whereas the deepsea challenger didn't. so they could take their time and do it right without pressure.
If you get the chance to watch Deepsea Challenge[1], it's worth the time. They were under a lot of pressure, which James Cameron was very proud of and the source of. They had more problems then you think, but was able to make it work.
of course. i meant they weren't under pressure to cut corners and ignore problems in order to make a profit. it was a different kind of pressure, to make sure they didn't miss any problems and to eliminate any risks, and possibly they risked the project being aborted if they could not solve all the problems.
