OSBM Bolt   

NBM OSBM BOLT ROCK 3.2M SW SIDE RD 38M S C LAY-BY OPP (81.773m above Lerwick datum, 2nd order, new 1978).

Location
Grid reference: HU 5206 8470.
Landranger 1: Shetland, Yell, Unst & Fetlar.
Landranger 2: Shetland, Sullom Voe & Whalsay.
Landranger 3: Shetland, North Mainland.
Structure: Rock outcrop.
Waypoint: OS2617.
The nearest fundamental bench mark is Duncansby Head, 242.19km to the southwest.