The Glass Bottom Boat[2] is a 1966 American romantic spy comedy film directed by Frank Tashlin and starring Doris Day, Rod Taylor, and Arthur Godfrey, with John McGiver, Paul Lynde, Edward Andrews, Eric Fleming, Dom DeLuise, and Dick Martin.

His widowed daughter, Jennifer Nelson, helps by donning a mermaid costume and swimming underneath his boat for the passengers' amusement.

Bruce's company created the GISMO, a gravitation control device which the U.S. Air Force plans to put into orbit in weeks and whose secret formula is sought after by the Soviet Union.

At his home, she meets electronics technician Julius Pritter and Edgar Hill, a CIA agent making sure the GISMO project is securely handled.

Cripps is suspicious of Jennifer because of things he noticed about her: She repeatedly calls the same number every day, counts the rings and then hangs up with the words "that's enough for now, Vladimir;" she burns papers alone at night in the office; and she has a shortwave antenna installed in her home.

There are innocent explanations for all of these things, which none of the people there know about: Vladimir is her dog, who gets his exercise by running through the house barking whenever he hears the phone ring; Jennifer read a note in the office explaining that old documents should be burned so that they cannot be stolen; and she uses her shortwave antenna to communicate with Axel.

Julius is confronted by his handler for only providing useless or publicly known information and is pressured into spying at a party which will be held by Bruce the next day.

The film stands apart from Day's other 1960s comedies due to animator-turned-director Tashlin's signature penchant for elaborate, cartoon-like gags and humor.

[11] In his June 10, 1966 review in The New York Times, Vincent Canby laid the blame at the feet of Tashlin: “… one of the few Hollywood directors to pursue the slapstick muse, (he) may some day make a really funny film, full of outrageous sight gags, mistaken identities and lunatic chases.

In the meantime, you can chalk up as another frantic failure "The Glass Bottom Boat," (which) chugged into the Music Hall yesterday, and promptly sank.

Miss Day,… seems now to recognize the existence of time… she is cast as a sweet widow, for no particular purpose, it seems, except to explain why such a lovely thing would be single in the summertime of her years.

… Unfortunately, Mr. Freeman's screenplay is predictable when it shows any inner logic, and simply absurd when it doesn't… the cast does include some of Hollywood's best farceurs, among them John McGiver, Paul Lynde and Edward Andrews.

The best of the lot, however, is a newcomer, Dom De Luise, …The picture's nicest inspiration may be the line, heard early, which explains Miss Day's marital status.

The DVD of The Glass Bottom Boat (released in 2005) includes three vintage featurettes (Catalina Island, Every Girl's Dream, and NASA), as well as the Oscar-Winning cartoon The Dot and the Line.