Aboard the cruise ship SS Happy Wanderer, Capt. Crowther (Sid James) grows increasingly miserable as last-minute replacements to his crew, including the cook (Lance Percival), doctor (Kenneth Connor) and first officer (Kenneth Williams), prove to be absolutely useless. In this nautical installment of the Carry On comedy franchise, gal pals Glad (Liz Fraser) and Florence (Dilys Laye) develop a fierce rivalry as they compete for the same man.