Felicitas mine: diving a flooded slate mine in Germany

Felicitas is a former slate mine in Germany that has become a well known destination for experienced cave divers. Closed for decades, it offers an unusual chance to explore a flooded system of underground galleries. Stable conditions and well preserved infrastructure make it one of the more interesting sites in Europe for divers moving into overhead environments.

History and location

Felicitas was worked for slate, a stone used widely in construction and industry. After the mine closed the galleries filled with water, and what was left is the diving environment that exists today. The site sits in wooded country and is open only to divers with the right experience and equipment.

Conditions and limits

Diving Felicitas is for certified cave divers only. What to expect:

• Visibility. Generally good, but sediment on the floor lifts easily and takes the visibility with it.
• Depth. The galleries sit at various levels, usually between fifteen and thirty metres.
• Temperature. Cold, typically between 6 and 10 °C.

This is an overhead environment. There is no direct route to the surface from inside the workings, and that single fact sets everything else about the dive.