: Can the anyone on the Story forum offer real help please?
I completely forgot how I cleared that level, unfortunately, and I can't remember anything about that particular route except that I wandered it for a while, too.
I CAN say that when the guide tells you to "jump down to this walkway" after grabbing Tycho's magical free-floating chip, you shouldn't actually jump straight from there; you need to double back to the pattern buffer and swim through the other underwater route (the one on the left, IIRC). Trying to take that shortcut will land you a story below where you're supposed to go, and there's no way up.
Kinda wonder if that chapter of the Spoiler Guide was written with Blasted Frogs in mind; the "shortest route to 3" looks a bit more straightforward there.