A TV movie continuing the adventures of the Love Boat gang.
Exercise doctor Charlene Thomas and her companion, Doris Johnson, board ship with the doctor booked to run an exercise class for the duration of the cruise. The woman introduced as Dr. Thomas is properly svelte, but her companion is considerably overweight. Isaac the bartender falls for the "doctor," not knowing -- as Julie and Vicki have found out -- that the two women have traded identities.
Meanwhile, Carol Darnell and Boyd Hughes come on board. The two have been involved for three years and Carol thinks Boyd is going to use the cruise as the setting for a long-awaited proposal of marriage.
The Doc has gotten hitched again, this time to a much younger woman named Cheri Sullivan. But he's unnerved when he discovers that his second ex-wife, Elaine Riskin, is on board on a honeymoon cruise of her own with a muscular young man named Steve.