In the first days at Murray Bay Nairne was in debt. In 1761, probably to purchase his captaincy, he had incurred a considerable obligation to his friend General Murray; where Murray got L400 to lend him is a mystery, for he was himself always pressed for funds. With everything to do at Murray Bay, mills to be built, roads to be opened, a manor house to be constructed, it was not easy to get together any money; for years the debt hung like a mill-stone round Nairne's neck. But he had always a certain, if small, revenue in his half pay and, in time, he acquired, chiefly by inheritance, what was, for that period in Canada, a considerable fortune. In 1766, when Nairne was in Scotland, General Murray, who had himself just arrived from Canada, wrote urgently to ask for payment. Murray owed to a Mr. Ross L8,000 and could not borrow one shilling in England on his estates in Canada; so he said "delay will be a very terrible disappointment to me." But this disappointment he had to bear. In 1770 the debt was still unpaid and may have remained so for some years longer. Happily the friendship between the former comrades was not impaired by their financial relations. Murray promised to put Nairne in the way of being "very comfortable and easy" in Canada, if he would follow his advice, but nothing came of his offer. For some years after 1761 Nairne thought of returning to Scotland, whither ties of kin drew him strongly. But his father's death in 1766 or 1767 helped to weaken these ties. In any case Scotland offered no career and he must do something to pay the debt to Murray and to provide for himself.