Mosterhamn is probably the oldest trading post between Bergen and Stavanger. (Svein Nord).
From times immemorial Mosterhamn has been a ships’ harbour. According to history this is supposedly the oldest trading post between Stavanger and Bergen. In 1582 the king made it illegal to sell timber to strangers north of Mosterhamn. The timber should be used to rebuild Bergen after the fire in 1561. There was also a guesthouse in Mosterhamn. In 1747 this was appropriated to Spissøy, east of Mosterhamn, but in 1797 it was moved back again. The sheltered bay at Mosterhamn was too small for large ships, so these were often anchored at Spissøy, and the seamen rowed into Mosterhamn at night. All that is left today of the old buildings is a half-hipped main building and a boathouse. Innermost in the bay there was a customs post for Bergen customs district. It was expanded in 1859 and took over from the closed customs station on Eldøy at Stord. The customs station in Mosterhamn was closed down in 1900.
- Endresen, H.G. (1950) Gjestgiverier i ytre led: Spissøy. I: Sunnhordland Årbok. Stord, Sunnhordland museum, s. 29-35.