Titan didn't have a flag, it only operated in international waters. But the surface support vessel has a Canadian flag, and Canada's launching an investigation.
The Guardian is reporting the submersible as registered in the Bahamas
A place known for tight regulations
Albeit perhaps not water-tight.
Depends one how much pressure is applied...
As the proverb goes, even a broken vise grips tightly when there are enough journalists in the workshop.
Flag of convenience. Where the country of record allows ships to register under their name as a way of generating revenue from foreigners. Bahamas will not do more than issue a statement, if that. You step foot on a flag of convenience boat with no prior reputation and you are effectively waiving any expectation safety.
It's like a .io domain or using Bitcoin. If you intentionally exit jurisdiction of a country you trust, you are on your own.
I hope the rescue teams sue the perpetrators' estates and corpos for their costs.