The first evidence of boats in Norway is in the form of petroglyphs – the rock carvings created by prehistoric people from the Stone, Bronze, and Iron Ages. In fact, the only evidence of Bronze Age seafaring is in the form of petroglyphs – there have been no boat finds from this period. Unfortunately, petroglyphs are very difficult to date. Some of the oldest petroglyphs in the world were discovered at Slettnes on the northern Island of Soroya in northern Norway. Due to sea level changes, the carvings of people, animals, and four boats can be securely dated to between 8,000 and 10,000 years before present. Some of the carvings are detailed enough that structural features of boats, such as a raking or rounded sterns, can be determined. One of the boats is clearly a fishing vessel, with a fishing line connected to a large fish (Sigfried, Stolting, 1997:). It is likely that the crafts depicted in the petroglyphs were skin boats – a frame of wood with the tanned hide of an animal wrapped around it. The waters upon which these vessels were used could become very rough at times. Though it might have been possible to utilize a logboat on the open sea, a skin craft could be built with a broader beam, and thus be more stable. Though logboats may have existed at the same time, they were used in different places and for different purposes (Brogger and Shetlig, 1951).
For more information about the citations, a short bibliography about Norwegian Seafaring can be downloaded here.