I have opened the door underwater with the plane propeller and got through the next room. I surface in a place with two exits. One is a door I can't open and the other way seems like a dead end, with one treasure. How do I open the door?
To the left is the door that cant open, thats the EXIT, and to the right is NOT a dead end, I forgot exaclty what I did, but there is something in there that opens the exit door.
Look around for a switch. Its not that hard to find.