In this level the water will rise and fall, sometimes the water just floats and you’ll need to swim with it to get where you want to go. Start by swimming up the path and into an alcove to the right where you can grab a Super Bell . At the left wall climb up to the Stamp then head back right, swimming up the water. At this point you need to scale the left wall since the water won’t take you high enough; in the hidden chamber is Green Star #1 .
Continue right to the Checkpoint Flag and a short stint with Plessie where you won’t gather any collectibles. Use the Cat Suit to climb up the back wall before continuing through so you can obtain Green Star #2 . Dash across the Donut Blocks then up to the Super Bell that’s in the ? Block . Head over to the water cubes that move up and down past the Spike Blocks. Don’t mess up or it’s certain doom. At the other end, ignore the pipe and climb up to a Cloud Cannon. Dash through this area to find Green Star #3 at the end then proceed to the Goal Pole.