Interesting read ...but some utter bunkum. This caught my eye...
"As they steamed through the North Channel with the lights of Londonderry off their port bow..."
Bloody good eyesight then - Derry is effectively 25 miles inland, at the far end of Lough Foyle, with some steep hills either side of the Lough at the "mouth " end. I very much doubt its possible to see anything of the city from out in the North Channel.