

Best for advanced divers, 3-104m, shore entry.
Dorothea Quarry is a flooded slate quarry in Mid Wales, recognised as one of the deepest accessible freshwater dive sites in the United Kingdom. The site features steep quarry walls, submerged machinery, and industrial debris, creating a complex overhead environment. Depths range from 3 to 104 metres, with an average of 40 metres. Visibility is typically between 10 and 30 metres. Due to the significant thermocline, water temperatures drop from 16°C in the shallows to 4°C at depth. This site is suitable only for advanced, deep, or technical divers. Shore entry is required, and a drysuit with an appropriate undersuit is strongly recommended due to the cold water conditions.
53.05510, -4.24123
Water temperature can be very cold regardless of season, so a drysuit and appropriate undersuit are strongly recommended rather than optional. Confirm current site access arrangements and any permit requirements locally before travelling, as these have changed periodically.
Access info coming soon
Recorded nearby, within 20km
Depth
3-104m
Visibility
10-30m
Skill Level
Advanced
Entry
Shore
Current
None
No, this site is intended for advanced, deep, or technical divers due to the extreme depths, cold water, and complex overhead environments.
The site reaches a maximum depth of 104 metres, with an average depth of 40 metres.
Access to the water is via shore entry.
Divers must manage risks associated with extreme depth, cold water, low visibility, and potential entanglement within the industrial debris and overhead structures.
A drysuit and appropriate undersuit are strongly recommended due to the cold water temperatures, which can reach 4°C at depth.
Diving at Dorothea Quarry in Mid Wales requires the following certifications: Advanced, Deep, Technical. Always dive within your training limits.
Visibility at Dorothea Quarry in Mid Wales typically ranges from 10 metres to 30 metres. Conditions vary with weather, tides, and seasons.