I was just watching Titanic and spent 20 minutes looking up the effects of hypothermia and discovering that Jack may have been alive and in stage 3 hypothermia when Rose let go, and because he sank instead of floated, he was in fact alive. It was a fun little time sink. What rabbit holes have you done down recently?
All these points are correct and there exists photos that support that Titanic looked quite different before she set off.