(written from a Production point of view)
Richard "Diamond" Farnsworth, Jr. (born 7 October 1949; age 64) is a stuntman, stunt actor and stunt coordinator who doubled Scott Bakula in the Star Trek: Enterprise episodes "Broken Bow", "Acquisition" and "Extinction". He received no on-screen credit for his work.
Farnsworth is the son of late actor and stuntman Richard Farnsworth and the father of stuntwoman Courtney K. Farnsworth. He has stunt doubled for stars such as Sylvester Stallone, Bruce Davison, and David James Elliott. Currently, Farnsworth is serving as Board Member of the Stuntmen's Association of Motion Pictures. 
He has been the stunt coordinator for hit television series such as Quantum Leap (1989-1991, starring Scott Bakula and Dean Stockwell), JAG (1995-2004), and Navy NCIS (2003-2007) and a stunt double for Scott Bakula in several films and television series, including Quantum Leap, Lord of Illusions, Color of Night, and Mr. & Mrs. Smith.
Among his stunt performing resume are films such as Rollerball (1975, with John Beck, and Robert Ito), First Blood (1982, with John McLiam and David L. Crowley), Ghost Busters (1984, with Michael Ensign, Paddi Edwards, and Tom Morga), No Way Out (1987, with Iman and Leon Russom), Color of Night (1994, with Brad Dourif, Jeff Corey, and Scott Bakula), Batman Forever (1995, with Rene Auberjonois, Kevin Grevioux, Ed Begley, Jr., Dana Hee, and Scott McElroy), Lord of Illusions (1995, with Scott Bakula and Famke Janssen), Pearl Harbor (2001, with Cary-Hiroyuki Tagawa, Manu Intiraymi, Raphael Sbarge, Leland Orser, and Justin Sundquist), and The Dukes of Hazzard: The Beginning (2007, with Christopher McDonald and Brian Avery).