Duncan knows everything there is to know about maps.
Duncan the Navigator became proficient at reading maps at an early age and ran away to sea where he was taken on by a group of Exiles as their on-board navigator. He was horribly seasick throughout his early voyages and got in the way of the crew with his over-eagerness and general clumsiness; the sea it seemed, was not for him.
He has dedicated himself ever since to building the most complete and accurate set of maps the world has ever known, from Piscatoris to Sophanem and with the discovery of a peopled archipelago in the East, so he's attached himself firmly to The Partner to make these maps, and assist with mapping the archipelago. As time has gone by he's found himself rendering assistance in recruitment; he would have a keen eye for people if he cared to develop it.