During the "I'll Take the Water" routine, in which the sailors fill their mouths with water in order to spray Lou Costello, Costello actually cracked up and spit his mouthful of water onto the floor, but the take was so funny it was kept in the film.

About ten minutes into the movie, Pomeroy Watson (Lou Costello) gets a ticket for jaywalking. After the cop gives him the ticket, he and Smokey (Bud Abbott) turn around to go back to the base. They pass a baby carriage in front of a store window with a very young girl in it. Pomeroy stops and says, "Hey, Smokey, look at the cute kid". That "cute kid" is Costello's daughter, Carole Costello.

This movie was actually filmed after Hold That Ghost (1941), but Universal released it first because the public wanted to see some "service pictures." After this film was released, Universal revamped "Hold That Ghost" to add a romantic subplot and some musical numbers for The Andrews Sisters and Ted Lewis' band, which hadn't been in the original cut.

The group gets assigned to the USS Alabama and sets sail for Pearl Harbor, HI, from San Diego, CA. With the movie being released on 30 May 1941, the real USS Alabama (BB-60) was commissioned on 16 Aug 1942 and earned nine battle stars during her service in World War II.

The movie makes extensive use of miniatures. After the film was completed Lou Costello took one of the battleships and put it in his swimming pool as a souvenir.

This film became an even bigger hit than Buck Privates (1941), becoming the sixth highest grossing film of the year.

The film contains the famous 13 x 7= 28 routine.

The film was rushed into production after their army picture, Buck Privates (1941), became a success.

The original trailer features brief shots from two scenes trimmed from the movie before release. The first features Costello in some business with a baby, evidently from the street scene early in the film; it may have been an extension of the business with the baby in the carriage (who was actually Lou's daughter). The second features Dick Powell and Claire Dodd sitting in a pond, likely intended to be part of the Hawaii scene.

Nick Condos and Steve Condos do dance in this film, to an unidentified song between 'A Sailor's Life for Me' and 'We're in the Navy Now'. If you see credits elsewhere for Frank and/or Harry Condos for this film, it likely came from bad information. Frank Condos and Nick Condos were the Condos Brothers in live performances from 1929 to the mid-30s, including 1 film in 1932. Harry was listed in a 1930 Playbill, but that's likely a misprint since Frank (also in the Playbill) was dancing with Nick at the time, and they took their act to Europe. All film credits after 1932 for Condos Brothers refer to brothers Nick and Steve Condos.

When the picture was sent to the U.S. Navy for approval, it refused to have its name associated with it because of the sequence at the end when Watson takes over a ship and does some decidedly un-military maneuvers with it. The producers, desperate to receive the support of the Navy, came up with the idea of having Watson accidentally taking a sleeping potion and dreaming the entire sequence. When this scene was shot and edited in, the Navy lent its backing to the picture.