Normally I keep blue coin notes separate but this episode is really just a blue coin episode. Lure each of the flying missiles into the various crates and they'll blow up so you get the coins. Some are easy, and some require you to make yourself a living target, then when the slow missile comes along, walk towards the crate so it follows you to blow it up.

Note you'll get hurt doing this so go water the flowers to get some life back.

When you're set with the coins, go close to the cannon so he starts throwing bombs at you. Water one, grab it and throw it right back at the cannon. He'll explode and you'll go into a puzzle.

For the first part, just hop across and grab the life mushroom in the middle chest. Now go up the trampolines.

For part 2, use the B-slide to slide all the way across as soon as the row appears.

For part 3, do a run and jump right when they appear to get to the turn. Then do the slide all the way to the end, and jump across the gap. You get a shiny!

Super Mario Sunshine Walkthrough