Some of those old single barrel muzzle loading guns with the long tubes were called 'marsh rails' here in Britain. I always regret not buying one in 8 bore percussion when I had a chance. They were used to poke over the edge of the big drainage ditches in the English Fenlands and shoot at groups of wildfowl on the water much in the manner if punt guns. I did have a single barrel breech loading 8 with a 42" barrel. Lagopus.....