Dennis Hopper's sailor suit was slightly darkened so it would read as white on film. During production, Hopper was spotted by military police who threatened to arrest him for wearing a dirty uniform.
The club patrons in the opening scene, in the Blue Grotto Bar, were friends of the crew. They appeared because there was no money in the budget to hire extras.
The seagull's beak was wired shut to prevent it from injuring the actors.
Peter Lorre was approached to play the role of Capt. Murdock, but the filmmakers couldn't afford the salary he demanded.