There are TONS of blue coins on this level.

First, there's a mushroom in crate on beach. There are:

blue coin in flower bed
blue coin in 2nd flame from left
blue coin on 2nd level of casino, on ledge on back.
blue coin from sign by beach loungers by 2 kids
blue coin in far right of water when facing beach
talk to guy at door, go in:
blue coin in ghost in attic
blue coin at end of path
blue coin in crates on 1st floor, down in floor.
Another through the hole where ghost was.


Now into the casino. Look at the wheels. Turn one manually to 777 by going close. Now go to the other and turn it to 777 and the curtains will open up. Try to spins the spots to make a face. If you work center-out it's not too bad because you can usually hit the edge ones one at a time

OK now a green chute. Go through the first 2 blocks. Hang out on the moving block and watch them move. you want to jump over just as the blocks are just moving away from you. There's a green one-up over to the right, try to sneak over to it. OK now over to rollig log. Cube seems suspiciously calm. When you hop on it, it's going to spin on 2 axes for a while (2 1/2 times) and then get close but not all the way . Jump over. If it gets back to start just hop on it to get it going again.

Super Mario Sunshine Walkthrough