Red Skelton, Eleanor Powell and a young Frank Sinatra stumble, sing and dance their way through a nefarious espionage plot by enemy agents in the wartime musical comedy Ship Ahoy.World War II. Band Leader Tommy Dorsey (himself), tap dancer, Tallulah Winters (Powell--Broadway Melody of 1940, Rosalie) and young band singer (Sinatra--From Here to Eternity, Ocean's Eleven) are the entertainment aboard a steamship heading to Puerto Rico. Also on board are hypochondriac mystery novelist Merton K. Kibble (Skelton--Around the World in Eight Days) and foreign spies who use a plot device from one of Kibble's novels to trick Winters into delivering a top-secret magnetic mine to the enemy. But when Kibble recognizes the plot device, Winters--who thinks she is working for the United States government--believes he is the enemy. But, somehow, after a series of comic mishaps, the spies are thwarted by the singers and dancers.