Carry on Jack (1964)

This is the tale of Albert Poop-Decker, a newly commissioned Midshipman (although he took 8 1/2 years to qualify). He joins the frigate Venus, and adventures through Spanish waters, mutinee and Pirates taking his Captain, his sweet-heart and his best-friend with him! With mistaken identities and shipwrecks awash, it's a surprise any of them live to tell the tale!