The Danches brothers, Abe, Ralph, and George, were Cleveland-based industrialists who made a fortune during World War II selling powdered eggs.

[4] The Danches brothers purchased a military surplus patrol boat and converted it into a "floating studio" on which the entire production crew embarked from San Diego to Alaska on 20 May 1947 for the shoot.

[6] Although this film marked Bromfield's first credited role, he would make his debut screen appearance in Sorry, Wrong Number which premiered one month before Harpoon was released to theaters.

[5] The production proved problematic, with the original actor playing "Red" having to be replaced after suffering severe injuries on the set[5] and extensive reshoots costing over $30,000 required after it was discovered some of the film was scratched.

[9] New York Times critic Bosley Crowther gave the film a "minor citation for effort", but dismissed its story as "hopelessly naive" and "childish", and the acting and direction as "painfully amateurish".