The Coast Guard responded to a report of a tank vessel which grazed the bottom of the channel on Dec. 19. No pollution was reported or sighted by response personnel. At 5 a.m., Coast Guard Sector San Francisco received a report that the Marshall Islands-flagged Tank Vessel Cape Brasilia had touched the muddy bottom of the Pinole Shoal Channel. The 577-foot tanker immediately moved back into deeper water without incident, assisted by two tugs. The Coast Guard immediately launched vessels from Coast Guard Station Vallejo and Coast Guard Station San Francisco to search the area for signs of pollution. At first light, an HH-65 Dolphin Helicopter from Air Station San Francisco conducted a thorough overflight of San Pablo Bay, with negative sightings of pollution.