Then OP has to die in international waters. And I think ships usually count as part of the country they are registered in. So if you die on a cruise ship it still counts like dieing in that ships owner country. And its not trivial to move a corpse out of a country, there are laws about that. So the country they plan to die in very mutch matters.
Heavily depends on the jurisdiction that applies to you when you die. People will be better able to help you if you disclose that.
I assumed international waters. I don’t think the home jurisdiction matters
Then OP has to die in international waters. And I think ships usually count as part of the country they are registered in. So if you die on a cruise ship it still counts like dieing in that ships owner country. And its not trivial to move a corpse out of a country, there are laws about that. So the country they plan to die in very mutch matters.