Search and recovery efforts continue for 'Glee' actress Naya Rivera at Lake Piru

BEVERLY HILLS, CALIFORNIA - NOVEMBER 06: Naya Rivera attends the Women's Guild Cedars-Sinai Annual Luncheon at Regent Beverly Wilshire Hotel on November 06, 2019 in Beverly Hills, California. (Photo by Axelle/Bauer-Griffin/FilmMagic)

Search and recovery efforts for missing mother and actress Naya Rivera continued Friday at Lake Piru with the help of rescue teams and innovative technology, Ventura County officials said.

"Today, we’re using a little bit less people in the search but more technology to help us find better clues. We have boats going out with specific missions to deploy sonar and help identify targets to investigate. We can’t put them all in the water at the same time. We have to plan these missions and coordinate them so they don’t overlap with one another. So, they’re going out in sort of a methodical way," Ventura County Sheriff Sgt. Donoghue said.

Security video was released Thursday that showed the 33-year-old parking her black Mercedes G-Wagon and then walking with her 4-year-old son, Josey, to the pontoon boat she rented on Wednesday afternoon. 

RELATED: Surveillance video, 911 call released amid search for ‘Glee’ actress Naya Rivera in Lake Piru

Nearly four hours later, the boat was found drifting in the northern portion of the lake. Her son was found sleeping alone with a life vest on and Rivera was nowhere in sight.

Rescue efforts started early Wednesday evening after someone on the lake made the 911 call

On Thursday, the search team included about 100 people including divers and an air crew.

Also on Thursday, Rivera was presumed dead by authorities.

An estimated 70 to 80 people continued with recovery efforts Friday with more resources, including cadaver dogs. Authorities said that rescue crews first use sonar technology to narrow down the search areas where they may find clues before sending in dive teams.

"In a lake, the visibility is not very good," Sgt. Donoghue said. "If you’ve ever watched underwater video and you’ve seen divers in the ocean, typically the visibility in the ocean water is much better. So, in the lake, the visibility is terrible. At this particular lake [in the area where Riviera’s rented pontoon boat was found] there’s a lot of trees and plants and such that are under the water that can cause entanglements. It makes it unsafe for the divers and it makes a more complicated search."

One of the divers told FOX 11’s Mario Ramirez he could only see about a few feet in front of him.

It is believed Josey is currently under the care of his father and Rivera’s ex-husband, Ryan Dorsey.

Rivera started acting at a young age. Jackee Harry shared a clip of the two of them from the show, “The Royal Family,” on Twitter and said she is praying for Rivera.

Rivera is best known for playing the role of Santana Lopez on the hit FOX show "Glee,” for six years.