California: Sonar and robotic devices were being used in what could be a long search for Glee star Naya Rivera, who authorities believe drowned in a Southern California lake.
Search teams on Lake Piru towed sonar devices across the surface of the water to scan for shapes below, before employing small remote-controlled appliances to explore the underwater spaces that show promise.
Divers are also still searching the murky waters, but fewer are being used than in the hours immediately after the 33-year-old was reported missing.
READ | Glee star Naya Rivera reported missing after boat ride with son
Surveillance video showed Rivera and her four-year-old son parking and entering the boat dock in the recreation area at the lake 55 miles (89 kilometres) northwest of downtown Los Angeles on Wednesday afternoon, authorities said.
She had experience boating on the lake.
About three hours later, the man who rented them the pontoon boat found the boy alone on it wearing a life vest.
The boy told investigators he and his mother had gone swimming, and he had gotten back on the boat but she hadn't.
With inputs from APTN
