One Wife Too Many — Susanne Marie Knight

Eighteen-year-old Andrea Ernst married for love. Wilson Struthers married to advance his career. On their Hawaii honeymoon cruise, Andrea learns the sordid truth. Disillusioned, she dashes out on deck during a storm. Fate sweeps her overboard.
Just as Wilson realizes that he loves his new wife, waves send her down into the bottomless ocean. He is devastated. An extensive search follows, but Andrea is never recovered. All hope for her survival is gone.
Or is it? Andrea resurfaces on the Big Island with no memory, only a feeling of dread when she thinks about her past. She rebuilds her life and is content never to discover her former identity.
Seven years pass. Although Wilson is still haunted by his loss, he marries again. But his current assignment is back in Hawaii... and he must face his tragedy once again. There he meets an attractive young woman, Anakalia, who somehow seems familiar to him. But who in the world can she be?