A husband and wife spend a holiday at the beach with their extensive family.

Roger Hobbs is a banker whose hopes for a quiet summer vacation are dashed when his wife, Peggy, decides that what they need is a little family "togetherness" at a cottage by the seashore. From the very beginning things go wrong. Their rented cottage turns out to be such a dilapidated Gothic eyesore that their cook, Brenda, leaves in a huff; son Danny prefers television to the beach; daughter Katey also refuses to go out because of the braces on her teeth; daughter Susan arrives with her unruly children and has a spat with her unemployed husband, Stan, who promptly leaves; daughter Janie's egghead husband, Byron, becomes the all-too-willing prey of Marika, a bikini-clad siren; and Peggy is openly wooed by Reggie McHugh, a yacht club romeo. But, by steady perseverance, Mr. Hobbs manages to restore family harmony. He conquers the house's rebellious pump, wins Danny's respect and admiration by guiding a small boat through a dense fog, overcomes Katey's shyness by introducing her to a good-looking youngster named Joe, helps Stan get a job by entertaining the privately alcoholic Mr. and Mrs. Turner, steers Byron away from Marika by implying that she is hopelessly schizophrenic, and outromances the pompous Reggie. When their vacation ends, Hobbs greets with something less than enthusiasm his wife's announcement that she has leased the cottage for the following summer.