- Category: Water Feature
- Type: Bay
- Latitude/Longitude: 54°17'47"N 3°25'13"W
- Eastings/Northings: 307658, 489910
- OS Grid: SD076899
- Mapcode Local: GBR 4LKR.9M
- Mapcode Global: WH71M.F8HN
Location and coordinates are for the approximate centre of Tarn Bay within this administrative area.
Geographic features and populated places may cross administrative borders.