On days like these, Millionaires like you, should be [joining the list of Titanic passengers].

Every safety manual is written in blood.

I'm okay with developing private submarines, but yes, it's a good idea to go through the long list of historical sub disasters and mitigate all reasonable contingencies.

Also, proper shakedown and stress-testing before going down with passengers.

A 1500 meter test doesn't count when going down 4,000 meters.