How do you get the first star in Jolly Roger bay Mario bros 64?

- In the bay, take control of the submarine from Lakitu.

- Head for the shipwreck in the distance while avoiding sea mines, squids, and eels and dive below it once you get close

- Enter to find a Big Boo. Chase it around until you catch it with your net, revealing a star under Boo.

- Collect it to end the mission.