In the year 1768, therefore, giving up his position on the Two Friends, he sailed as a passenger in the brigantine John, bound for Kirkcudbright. It happened that the captain and mate of the vessel both died of fever during the voyage, and at the request of the crew Paul assumed command and brought the vessel safely to her port. Currie, Beck & Co., the owners of the John, were so pleased with this exploit that they appointed young Paul master and supercargo of the vessel, in which he made two voyages to the West Indies. He was a captain, therefore, and a merchant at the age of twenty-one. The owners of the John dissolved partnership on the completion of his second voyage, and disposed of the ship, giving Paul the following honorable certificate upon his discharge from their employ: "These do certify to whom it may concern, that the bearer, Captain John Paul, was two voyages master of a vessel called the John, in our employ in the West India trade, during which time he approved himself every way qualified both as a navigator and supercargo; but as our present firm is dissolved, the vessel was sold, and of course he is out of our employ, all accounts between him and the owners being amicably adjusted. Certified at Kirkcudbright this 1st April, 1771. "Currie, Beck & Co." One incident in his West Indian service is worthy of mention, because it afterward crept out in a very ugly manner. On the second voyage of the John the carpenter, a man named Mungo Maxwell, formerly of Kirkcudbright, who had been mutinous, was severely flogged by the order of Paul. Maxwell was discharged at the island of Tobago. He immediately caused Paul to be summoned before the judge of the vice-admiralty court for assault. The judge, after hearing the testimony and statement of Captain Paul, dismissed the complaint as frivolous. Maxwell subsequently entered on a Barcelona packet, and in a voyage of the latter ship from Tobago to Antigua died of a fever. Out of this was built up a calumny to the effect that Maxwell had been so badly punished by Paul that he died from his injuries. When Paul was in the Russian service years afterward the slander was enhanced by the statement that Maxwell was his nephew. There was nothing whatever in the charge.