Reply To: Underwater levels
They are hard indeed. You need to be fast and precise, and the controls are quite slippery.
In the Pod Race level (the one with the single long segment), there is a hidden pump about three quarters into the race; if you get to it, it should give you enough air to finish comfortably.
https://vgmaps.com/Atlas/SuperNES/EarthwormJim-TubeRace.png