Haulbowline (Irish: Inis Sionnach), is the name of an island in Cork Harbour off the coast of Ireland. The world's first yacht club was founded in Haulbowline in 1720. The western side of the island is the main naval base and headquarters for the Irish Naval Service, with the eastern side previously used for heavy industry. Since 1966 the island has been connected to the mainland by roadbridge.