Ghost Pirates of the Sea-erra Madre

You follow the crack along the ocean floor, hoping that it will open up and allow you to discover their source.

As you move along bubbles continue to escape from the crack, but it grows no wider and after several minutes you begin to feel somewhat impatient.

You could use the Seeker Jr.'s laser cannon to try to blast the crack wider or you could learn what patience is and continue to follow the crack along the ocean floor.