Philip Courois married an unknown woman in 1771 when she was 19, place not known. Because of his untimely death they had only one child.
Philip and his older brother Hugh were joint owners of a large sailing ship which was their means of being West India merchant adventurers. Legend has it that the brothers owned a West Indian island, in the Leeward islands near St Kitts, which they used as their base in the area. The story goes that a trusted manager stole a considerable fortune from the enterprise and ran away with it. Upon discovering the loss Hugh sent word to Philip who was in Scotland at the time, and set out in pursuit in an open boat. Philip caught up with Hugh and joined him in the long chase from island to island. Hugh died of a pneumonia during the chase. Philip wrote to Scotland telling of Hugh's death. Less than six weeks later he also contracted the mysterious tropical fever which killed him at 22 years of age.
The legend continues that after their deaths their large estate in the West Indies was fraudulently stolen away from the family, which resulted in financial hardship for his widow and child.