The 'beautiful' barge was definitely large . . . but that is where any resemblance to the advert ended. For instance, there was absolutely no mention that she had obviously run into or been run into by something. A dock probably, but it could have quite easily been war wounds from a volley from long nines — she looked that old and battered!
Marie Browne, Narrow Margins (Mid-Glamorgan: Accent Press Ltd., 2009)
From all this we can ascertain that a “long nine” was a cast iron 9-pounder with a barrel length of at least nine feet. And while it was certainly used as a chase piece on frigates and ships of the line but it also served as the main battery on ship-sloops in the 18 and 20 gun category.