Ted Wilford #14: The S.S. Shamrock Mystery, by Norvin Pallas (epub/Kindle/pdf)
Strange doings on an ore boat! Ted and Nelson to go undercover as unskilled deck hands on the S.S. Shamrock unravel the truth. Is it just bad luck, or is something more nefarious afoot? Stir in a stowaway, a realistic shipping setting, and a series of puzzling events and you get a classic entry in the Ted Wilford series.
#14 in the Ted Wilford series.