My great-great-great grandmother, Catherine Black, wife of Robert Hamilton of Calton, Glasgow, was born in Rothesay, Bute in 1798 (?). Her death certificate states that her father was Archibald Black, a "seaman", and her mother was Rachel Clark (This was reported by one of her daughters, Sarah Hamilton, wife of James Brown of Rutherglen, Lanarkshire).
I can't find a Rachel Clark from this time, but I did find a Catherine Black born to an Archibald Black, "skipper of the Rothesay packet" and Catherine McConechy. Archibald Black's father was John Black, "sometime ferryman at Kilmichael" and Catherine McConechy's father was John McConechy, Farmer at Cranslagvourity (or something like that).
I don't want to go too far down the road with this Archibald Black, in case he's not mine, but would welcome any input.