To comply with the demands of their wacky mother's will and settle her estate, the estranged Laverne sisters—anxious Electra, free-spirited Calliope, and type-A artist Elli—must cruise the British Isles together for two weeks. Although none of the ladies are excited, the adventure promises tremendous payoff, if they can outlast the tension. In the oceans of their ancestors, the trio could voyage into the uncharted waters of affection or sink into the icy depths of rivalry. The ladies quickly discover that this family vacation will not offer the tranquility the travel agent promised. Stuck on a floating petri dish of chaos, the sisters try to find their sea legs along with commonalities and compassion for one another, but their complicated history and hot-and-cold communication styles keep them at odds. Through quirky ship activities, dubious land excursions, revelations of long-held family secrets, and an ever-growing list of embarrassing moments, each sister must navigate her feelings about the family's dynamics as well as her own crisis (a crumbling marriage, a business disaster, or a blossoming midlife romance) to coast into calmer waters, pulled by the ties that bind them as a true family.