Yeah, no kiddingunsinkable cruise ship hits iceberg and goes to the bottom? Who could have possibly seen that coming?
maybe they can get James Cameron and Leonardo DiCaprio together for a hollyoood movie.. Cameron does his research well, Oh wait, they did that one, huh? ;-)
so I guess it was a submerged chunk of ice with some rocks on it and not a sub or an alien craft scaring them away from a secret underwater base. :-}