- Star Coin 1: Jump on the first Bullet Bill cannon and jump to the Star Coin over the gap in between the cannons.
- Star Coin 2: In the underwater part, activate the P Switch and swim to the Star Coin.
- Star Coin 3: After exiting the underwater part of the level, jump on the three platforms and jump to the Star Coin before the King Bill destroys them.
Hidden Luigi image
After going in the underwater section (not in the Mini pipe), hit the Brick Block with a P Switch on it and let a Torpedo Ted hit that block to activate it. After that, swim above the exit pipe as fast as you can to reveal a picture of standard Luigi from Super Mario Bros. swimming.