Fig. 4. Experimental insights into Greenland Norse seafaring capabilities: example of a larger expeditionary sailing vessel.

This is a Norwegian fembøring, a direct descendant of the Norse clinker tradition used in Greenland (Vestfjord, northern Norway, May 2022). Only these larger sailing ships, owned and sponsored by richer farmers and elites, would have been capable of reaching the North Water Polynya during single-summer expeditions. One major risk was becoming trapped in the expanding late-summer pack ice, forcing the crew to overwinter en route, as evidenced by the Kingittorsuaq runestone (Fig. 5) carved during the Spring, and dating to ca. 1250 to 1300 CE (see Supplementary Text). Photo: G.J.