Open Water 3: Cage Dive is a 2017 Australian found footage survival horror film directed and written by Gerald Rascionato, and released by Lionsgate. The third installment of the Open Water film series — although the film is a stand-alone sequel and only connects to the other films in theme, not continuity — the plot follows a trio of vacationing Americans in Australia who are filming an audition tape for an extreme reality TV show on a cage diving excursion. Before they know it, a rogue wave capsizes and sinks their boat leaving them stranded in the ocean. The film is presented as a mockumentary and perpetuated as true events; though most of the film is first person footage from the characters with time stamps throughout, in the vein of Paranormal Activity.

The film bears similarities to another 2017 shark attack survival film featuring a cage dive excursion gone wrong, 47 Meters Down. The method of "cage dive disaster" in each film differs with Cage Dive involving a rogue wave capsizing the boat while the former film sees a rusty winch break, trapping the protagonists underwater within the cage. The notable difference between these two films is that Cage Dive does not keep its protagonists within the cage, but rather leaves them in the open water among hungry sharks.