- Category: Water Feature
- Type: Island
- Latitude/Longitude: 51°41'13"N 5°9'44"W
- Eastings/Northings: 181511, 203431
- OS Grid: SM815034
- Mapcode Local: GBR G3.JVL2
- Mapcode Global: VH1RW.GVRM
Location and coordinates are for the approximate centre of Calm Rock within this administrative area.
Geographic features and populated places may cross administrative borders.