The Castaways by Elin Hilderbrand
Greg and Tess MacAvoy are one of four prominent Nantucket couples who count each other as best friends. As pillars of their close-knit community, the MacAvoys, Kapenashes, Drakes, and Wheelers are important to their friends and neighbors, and especially to each other. But just before the beginning of another idyllic summer, Greg and Tess are killed when their boat capsizes during an anniversary sail. As the warm weather approaches and the island mourns their loss, nothing can prepare the MacAvoy's closest friends for what will be revealed.
Once again, Hilderbrand masterfully weaves an intense tale of love and loyalty set against the backdrop of endless summer island life.
All of Elin's novels have been set on and around Nantucket Island where she lives. She is a graduate of Johns Hopkins University and was previously a teaching & writing fellow at the University of Iowa.