After House, The by Mary Roberts Rinehart (1876 - 1958)

Ralph Leslie, a brand-new MD, realizes that a life of adventure holds more appeal than hospital rounds and daily clinics. Is it good luck, bad luck, or just fate that lands him as deck steward on the schooner Ella? Because once in open water, the booze flows too freely, old animosities resurface, and new ones form. And then someone starts behaving badly, so badly, in fact, that people are turning up dead. It becomes Leslie’s job to get the Ella, its crew and passengers, and the evidence back to port before the murderer strikes again. (Summary by Tom Penn)