Dead Calm (Perennial library Book 655)

On the open waters of the Pacific, a couple encounters a stranded madman
Rae and Ingram are nineteen days out of the Panama Canal, sailing slowly across the wide, flat Pacific on the Saracen, when they find Hughie Warriner in his dinghy. He was on a pleasure cruise in his yacht, the Orpheus, he says, when food poisoning killed his passengers and his ship began to sink. After an alleged ten days of desperately fighting to stay afloat he spied the Saracen, and rowed to his salvation. Finding the stranded yacht, against Warriner’s wishes, Ingram boards the stranded Orpheus. There he finds Warriner’s passengers—very much alive, and hungry for revenge against the man who attacked them and left them to drown. Ingram tries to get back to his ship, but is too late. Warriner escapes with his yacht, taking Rae hostage, and Ingram hasno means to save them but tattered sails, a sinking ship, and rage that burns hotter than the merciless Pacific sun.