Skarnsund or Skarnsundet is a strait in the Trondheimsfjord connecting the inner section, Beitstadfjord, with the outer section. The 0.5-kilometre (0.31 mi) wide Skarnsund is located between two municipalities: Inderøy to the east and Mosvik to the west. On the Inderøy side of the strait is the village of Vangshylla and on the Mosvik side is the villages of Venneshamn and Kjerringvik. The strait has a strong tidal current with a maelstrom.[1]
Skarnsund was crossed by the Vangshylla–Kjerringvik Ferry (car ferry), operated by Innherredsferja, prior to 19 December 1991. On that date the new 1,010-metre (3,310 ft) long Skarnsund Bridge was opened. The bridge is part of Norwegian County Road 755. Skarnsund is a noted site for both sports fishing and underwater diving.