I got past the tube by accident, but it was nice nonetheless :) I'm glad that that happened, because I don't think I would have done it on my own - you're right that at this point it's unique. You do, however, get a subtle clue in the form of the broken pipe in the room where all the crabs are, just above it - it sort of points you towards realizing you might be able to break it somehow.

I always have the power to surprise ;)