Corsairs of Cthulhu:  Fighting Mythos in the Golden Age of Piracy, is a Call of Cthulhu 7th edition source book  licensed by Chaosium.
This 300 page book features the beautiful art work of  Joel Bisaillon,  brought to you by New Comet Games, the same people who brought you the award-winning Call of Cthulhu books Devil's Swamp and A Time for Sacrifice.

Corsairs of Cthulhu includes everything you need to play pirates or privateers in Call of Cthulhu and also includes a full campaign, rules to play as standard CoC or Pulp Cthulhu.