I just remembered something! The manual for the first game says that some of the best things can be found just outside the range of the screen. In "Down the Tubes," when you're piloting (I think) the second bathysphere, there comes a point where you can indeed find another air uplink in the lower-left corner of the screen. It's hidden behind some coral. Be extra careful when getting it, though, or else you'll crack the glass!
RE: That One Level
I just remembered something! The manual for the first game says that some of the best things can be found just outside the range of the screen. In "Down the Tubes," when you're piloting (I think) the second bathysphere, there comes a point where you can indeed find another air uplink in the lower-left corner of the screen. It's hidden behind some coral. Be extra careful when getting it, though, or else you'll crack the glass!