Pretty sure coast guard did step in to help the ship, but the ship was hiding from authority. Once the call went up because was there. Like the RNLI rescue small boats in English channel. (Somthing some.idiots on the right are claiming is reason not to give to the charity)
The submersible was a boat on a ship the ship.may be bound by imo or it’s flag star rules. I work in maritime software. regulation around Solas and imo rules are mental I mean we only moved ships off xp in last few years as the xp for embedded systems had been thoroughly tested and type approved, e.g. two 90day test runs