UPDATE: The Coast Guard says it has recovered two children believed to be abducted by their father from South San Francisco.
The guard spent most of the day Friday tracking a stolen sailboat believed to be carrying the man and the children.
Authorities say the sailboat named "Unleashed'' was spotted off the San Mateo County coast three days after 43-year-old Christopher Maffei allegedly abducted his 3-year-old daughter, Brooklynn, and 2-year-old son, Devin, from their mother's home.
Chief Petty Officer Mike Lutz says a Guard airplane followed the boat south to Monterey Bay. The children were in safe hands by 8:30 p.m.
After searching desperately for a father who police say abducted his South San Francisco children this week, police announced Friday that all three have been spotted off the coast of Half Moon Bay.
Fishermen saw Christopher Maffei and his children - Devin, 2, and Brooklynn, 3 - 50 miles off Pillar Point by the San Mateo County coast 4 a.m. The U.S. Coast Guard was dispatched to retrieve the children, police said. At this point, everyone appeared to be safe.
By 11 a.m., a C-130 helicopter was hovering around the yacht, and a U.S. Coast Guard cutter from Treasure Island was en route to the family.
The children's mother, Jennifer Hipon, was anxiously awaiting her childrens' safe return at her South San Francisco home. She said that Maffei, whom she had dated in the past, had recently returned from Thailand, and had wanted to see his children.
She agreed, but added that he had seemed increasingly anxious to be near the kids. His zeal to see the children scared her enough to seek a restraining order against him, she told NBC Bay Area on Friday. She was at the courthouse in Redwood City on Tuesday seeking that order, when she said Maffei went to her home on James Court about 3 p.m.
Her mother was babysitting, and Hipon said he just grabbed the kids, one under each arm.
Police then believe Maffei took off in a rented white Ford Fusion to the Bellena Isle Marina in Alameda, where he later allegedly stole a yacht and sailed away. Investigators say that Maffei had been at the habor two weeks before, and had asked about buying a boat.
The rental car was discovered at the marina and towed for evidence.
The yacht is named "Unleashed" and has "San Francisco, CA" painted on the stern. Before Friday morning's sighting, the yacht was last see at about 6 p.m. on Wednesday in the area of Mare Island near Vallejo. Maffei has said in the past that he would like to sail to Monterey or Mexico.