 Between 1959 and 1973 the first 38 volumes of this series were systematically revised as part of a project directed by Harriet Adams, Edward Stratemeyer's daughter.The original version of this book was rewritten in 1967 by Tom Mulvey resulting in two different stories with the same title.While boating on Barmet Bay, the Hardy boys spot a periscope from a submarine and then nearly crash into a rented speedboat driven by a Mexican man named Pancho Cardillo.