Single sheet. Hand coloured manuscript drawn on vellum. The animal skin retains a vestigial neck. Scale [circa 1:2,000,000 (lat)]. The chart contains a latitude bar and rhumb lines. Three bar-scales are aligned to tracks on the voyage to Narva. A dotted-line circle joins the compass roses. There are numerous prick holes, probably made by the navigator's dividers. The chart shows only the land sighted in voyages from England to Narva and to north Norway.

Borough was Chief Pilot of the Muscovy Company which imported timber, cordage and tar. Narva was under Russian control from 1558-1581. When William Borough (1537-98) was sixteen, he had sailed with his brother Stephen on an expedition to find the North East Passage to Cathay. He became a distinguished navigator and Master of Trinity House.