Maybe they want to interact on an instance that’s defederated by/defederates another. That’s the case with Beehaw, although a lemmy.ml account would work just fine for it too.

If you mean the OceanGate submarine, it seemingly spectacularly imploded after its carbon fiber structure gave in to various microfractures. If that really is what happened, the water pressure killed the crew faster than their brains would’ve processed anything.