Sixty-year-old Rodger McCauly is devastated when he learns that he has contracted tuberculosis and has only one year to live. Determined to fulfill his lifelong dream of sailing to Tahiti, he embarks on the voyage abandoning his twenty-seven-year mortgage brokering business, his wife Irene, and his three grown children. He purchases a thirty-one-foot Tahiti ketch, the Sea Witch, from fifty-eight-year-old Helen Davis, an experienced sailor. After learning that Rodger has little experience sailing, Helen volunteers to become the boat's skipper. A widow, Helen seeks adventure and has always desired to travel to Tahiti.
As Helen teaches Rodger the intricacies of sailing, they begin to form a relationship far deeper than skipper and mate. On their runaway adventure to Tahiti, Rodger and Helen must navigate not only the threats of the sea and the weather, but also the details surrounding his failing relationship with Irene. With their new crew member, a stray dog named Bilgee, Rodger and Helen hope their love can survive the impossible.