The King's Privateer by Dewey Lambdin
1783: Officer Alan Lewrie becomes His Majesty's secret agent. Fresh from war in the Americas, Lewrie finds London a pure pleasure. Then, at Plymouth, he boards the trading ship Telesto to find out why merchantmen are disappearing in the East Indies.
Between the pungent shores of Calcutta and teaming Canton, Lewrie discovers a young French captain, backed by an armada of pirates, on a plundering rampage. While treaties tie the navy's hands, a King's privateer is free to plunge into the fire and blood of a dirty war in the South China Sea.
The King's Privateer is perfect for fans of Bernard Cornwell and Patrick O'Brian.