Missing is 69-year-old Diana Wolking.
Wolking was last seen Wednesday wearing a black rash guard, black and white bikini bottom with a scuba tank and black fins.
An MH-65 Dolphin helicopter crew from Coast Guard Air Station Barbers Point is currently searching along with the crew of the . Hawaii County Fire Department is searching with helicopter and rescue boat crews.
An Urgent Marine Information Broadcast has been issued alerting mariners in the area to keep a sharp lookout and report any sightings to the Coast Guard Sector Honolulu Command Center.
Watchstanders at Sector Honolulu received notification at 7:20 p.m. from good Samaritans on the beach who witnessed Wolking enter the water just before sunset. After more than an hour, they noticed her truck still parked at the beach and could not locate any sign of her in the water or near the beach.
Anyone with information that may help locate Wolking is asked to contact the Coast Guard Sector Honolulu Command Center at 808-842-2600.