This musical -- a concoction of comedy, songs, dancing, and war-time patriotism mixed together with a spy spoof plot -- opens with Tommy Dorsey and his band swinging through "Hawaiian War Chant" while Eleanor Powell taps away. Powell, it turns out, is Tallulah Winters, the band's official tap dancer, and she and the orchestra are taking an ocean liner to Puerto Rico for their next gig. Also on board are some enemy agents, anxious to secretly and safely transport their stolen plans, which include a prototype magnetic mine that can make play a big role in the war. Utilizing a plot device from a novel by Merton K. Kibble (played by Red Skelton), the enemy agents pretend to be working for the U.S. government and enlist Winters to help them with their plans. A series of misunderstandings and confusions ensue, including a baggage mix-up that leaves Kibble unwittingly in possession of the mine. Eventually Winters discovers that she has been duped and works to set all things right. Ship Ahoy takes advantage of the talents of its musical stars -- including Frank Sinatra and Jo Stafford -- to offer a nice spread of musical numbers, including "Last Call for Love," "I'll Take Tallulah," "Poor You," and "On Moonlight Bay."