Chick and Mike were diving, searching for a giant oyster and the pearl it was fabled to contain. While they found the oyster, they were forced to surface because they ran out of air, and returned to their boat.
Right when they returned to their boat, Stingray approached the boat. The boat was in a WASP protected area, and diving and boat traffic was not allowed, as the area is set aside for oyster farming. Stingray then escorted the boat out of the area and back to Marineville.