"Bering Sea Gold" (9 p.m., Discovery): In Season 4, ambitious treasure hunters continue to brave frigid temperatures and brutal conditions -- all as we watch from the warm comfort of our couches.
"The Knick" (10 p.m., Cinemax): Dr. Thackery (Clive Owen) orders his underlings to practice some of their surgical procedures on pigs. And no, they're not interested in making bacon.
"BoJack Horseman" (Netflix): The streaming giant makes its first foray into adult animation with this kooky series about a beloved 1990s sitcom horse (voiced by Will Arnett) who now is living in a Hollywood bachelor pad and coping with being a TV has-been. Wonder what Mr. Ed would think.
Also on Friday: