Ship Ahoy, a patriotic musical comedy of the WWII era, swings to the tempo of it's big-band times. Eleanor Powell plays a leggy lead dancer on a cruise ship who is asked to transport a mine to Puerto Rico. Neither she nor her pulp-fiction-author beau (Red Skelton) knows she's actually working for spies; who got the idea from one of his potboiler novels! The supporting cast includes Bert Lahr (the Cowardly Lion in the Wizard of Oz) and Virginia O'Brien (Till the Clouds Roll By). All of the festivities are set to the swing of Tommy Dorsey and his Orchestra featuring a very young Frank Sinatra as vocalist.