Super Mario 64 on N64 - Level 9: Dire, Dire Docks - Coins and overview
Level Stars

Overview

1. There is a shell inside a clam at the bottom of the second pool.
2. You have to complete the level "Bowser in the Fire Sea".
3. There is a big hole in the second pool that takes you outside Peach's castle. Careful, the current pulls you toward it.

The 8 Red Coins

All the red coins are above the second pool; you must have finished "Bowser in the Fire Sea" to get them. Press the purple button and take the steps on the left that appear. To get all the red coins, you just need to grab onto the black and yellow poles. Go to the left one first, then take the other 4. Move from one pole to the next to catch them all and take the remaining one.

Bonus Star: 100+ Coins

There aren't many extra coins in this level (106), so you have to take one of the 2 rows of coins from picture 1, near the whirlpool that pulls you in, as well as all the red coins. There is a blue button that makes 6 blue coins appear above the second pool, on the path of the red coins.