Ventura County Sheriff’s Office is keeping the world informed on their search for missing Glee star Naya Rivera at Lake Piru. Authorities provided a video update from their late Friday night mission on July 10, shedding light on just how tough searching the California reservoir is. The clip shows a remotely operated vehicle (ROV) they deployed 30 feet down to search the depths of the lake. “Here’s the ROV used by @TulareSheriff in the search for Naya Rivera at Lake Piru today,” the caption read. “This is one of many resources being used, along with side scan sonar, dogs, and divers.”

©@nayarivera

“Here’s an example of the underwater visibility at a 30-foot depth in Lake Piru,” the second part read. The ROV was enlisted to check out a dark shape at the bottom of the lake. As the footage shows, it was turned out to be just a tree branch. Earlier on Friday, the department stated during a press conference that sonar equipment has been extremely helpful in focusing the diver’s search of the nearly two mile long and (at times) 130-deep lake. Though none of the shapes detected have been Naya, this technology is key.

“Unfortunately, they did not locate Naya Rivera.” Captain Eric Buschow of Ventura County Sheriff’s Office told reporters at the briefing. “They are still searching.” He went on to call the situation “difficult” since “we don’t know if she’s going to be found five minutes from now or five days from now.”

Naya Rivera was first reported missing at the lake on Wednesday, July 8. The 33-year-old actress vanished after renting a pontoon boat with her four-year-old son Josey Dorsey. According to reports, the child was found hours later by himself in the vessel on California’s Lake Piru. At a news conference (via CNN), Eric revealed that Josey said he and his mother went swimming, but Naya did not get back in the boat.