[1] On television, his most notable role is probably as the brash, plain-speaking American guest, Mr. Harry Hamilton, in the Fawlty Towers episode "Waldorf Salad".

[3] Boa attended the University of Western Ontario, graduating in 1952 with a degree in theology, then spent a brief period playing professional football for the Calgary Stampeders in 1952.

In a 1959 interview, when he was aged 29, he said he had also written poetry, a novel and film scripts, and hoped to make a living combining writing and acting.

[6] He also played the Marine colonel in Full Metal Jacket (1987) who chastises Matthew Modine's character over having a peace pin on his lapel while having "Born To Kill" written on his combat helmet.

[8] Other television credits include: Fawlty Towers, The Avengers, Out of the Unknown, The Champions, The Troubleshooters, The Saint, Ace of Wands, Special Branch, The Onedin Line, Z-Cars, The New Avengers, The Professionals, The Omega Factor, Dempsey & Makepeace, Astronauts, Hart to Hart, Remington Steele, Howards' Way, the 1979 miniseries A Man Called Intrepid, the 1988 television film The Bourne Identity, Tales of the Unexpected, As Time Goes By, Road to Avonlea, Kavanagh QC, Bulman and Warship.