Dive-site story
Carrière des Fresnais is a flooded former slate quarry located in the historical slate-mining region of Trélazé. The quarry basin features dramatic sheer slate walls, stepped extraction benches, and remnants of industrial equipment left behind after operations ceased. Used primarily by regional diving clubs for deep training and skill development, the site offers an atmospheric inland diving environment with distinct thermoclines and freshwater fauna roaming among submerged structures.
Sheer slate rock walls displaying historical quarrying marks and stepped ledges
Submerged industrial artifacts and training platforms anchored throughout the basin
Encounters with freshwater predatory fish lurking along the rocky ledges
Location
Use the map to plan with your operator and confirm the exact entry point on the day.
Seasonality
Warmer surface layers make entries comfortable during late spring through early autumn, though deep layers remain cold year-round.
Marine life
| Species | Likelihood | J | F | M | A | M | J | J | A | S | O | N | D |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Northern pikeEsox lucius | Common | ||||||||||||
| European perchPerca fluviatilis | Common | ||||||||||||
| Common carpCyprinus carpio | Common | ||||||||||||
| Signal crayfishPacifastacus leniusculus | Common | ||||||||||||
| Wels catfishSilurus glanis | Rare |
Marine forecast
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