The Rover Boys on the Ocean is the second volume in the first Rover Boys series. Even before they get out of the first chapter, they have a run-in, literally, on the water with the sneak of Putnam Hall, Mumps. We saw lots of Mumps in the first volume and the evildoer Dan Baxter. The two of them, along with Dan's father, Arnold. The Baxter, aided by Mumps and other bad guys kidnap Dora Stanhope, and what follows is high adventure on the high seas.
Edward Stratemeyer wrote more than 1,300 books himself, selling over 500 million copies. In addition to 10 Dave Porter books, Stratemeyer wrote seven series with mostly a military nature. He also created Nancy Drew, The Hardy Boys, The Rover Boys, The Dana Boys, Bomba the Jungle Boy, and Tom Swift. He wrote under seven pen names and employed a number of ghost writers for whom he wrote plot outlines. The "Stratemeyer Syndicate" was a large organization and controlled a number of publishers.