Wealthy Rollo Treadway suddenly decides to propose to his neighbor across the street, Betsy O'Brien, and sends his servant to book passage for a honeymoon sea cruise to Honolulu.

Because the pier number is partially covered, he ends up on the wrong ship, the Navigator, which Betsy's rich father has just sold to a small country at war.

At first, they have great difficulty looking after themselves (both used to being served), but adapt after a few weeks, with Rube Goldberg - like devices to make coffee, open cans and boil biscuits.

While Rollo dons a deep sea diving suit and submerges to patch the hole, the natives canoe out and take Betsy captive.

While Keaton's Art Director Fred Gabourie was scouting shipyards in San Francisco for another project, The Sea Hawk, he was shown the former USAT Buford, a 5,000 ton, 500 foot ship that was being sold for scrap metal.

Prior to The Navigator, the Buford's most controversial service had occurred in 1919–20, during the First Red Scare, when it was used as the "Soviet Ark" to deport 249 "undesirables" from the United States to revolutionary Russia, among them the noted anarchist Emma Goldman and Alexander Berkman.

Keaton immediately began planning a film centered around the Buford and had producer Joseph Schenck charter the boat for $25,000 with a crew and sail it to Los Angeles.

[3] Keaton renamed the ship Navigator and his crew began remodeling the interior, installing film lights and painting it.

However the extra weight in the pool caused the bottom to cave in and Keaton had to move production to Lake Tahoe to finish the underwater scenes.

That is to say it's both commonplace and novel, with the latter sufficient to make the picture a laugh getter..." Variety also noted the novelty of Keaton's deep-sea diving costume and settings and praised "an abundance of funny business" in some of the film's underwater scenes.