Ordinary fiberglass is rejected as a pressure-hull material in favour of titanium or specialized steel made to exacting standards. A game-style controller is less concerning than a control system without wired connections and multiple backups. A small unmanned vehicle can land after a fault. A deep submersible may be beyond any possibility of outside repair or rescue, so every control failure carries far greater consequences.
Notable Point · 45:20-50:49
Deep-diving submersibles demand proven materials and backups
A discussion prompted by the Titan loss contrasts acceptable drone controls with the much stricter engineering needed for a crewed deep-diving vehicle.