Okay, the modified Titanic level has been completed and is now in the forum under "The TITANIC resurfaces!" Please use the link provided there for the updated level, which now includes a timed closing watertight door... I'd be surprised if anyone else can beat it.
PS - I know it's hard to find in the list, but if you could rate the level or leave feedback/comments on the newer post, it would be very GREATLY appreciated! Thanks and good luck.