Germany – Mines & Caves

Germany has no open cave-diving region like France or Mexico, but centuries of mining have left flooded galleries that a few operators open to divers. The largest is the Nuttlar slate mine in the Sauerland, with about 12 km of flooded passages, a cavern area for trial dives and courses up to full mine diver. In Saxony the old lime mine at Miltitz near Meissen is dived only on announced winter weekends, and the Felsendome Rabenstein in Chemnitz offers guided dives in its two flooded levels. The famous karst springs of the Swabian Jura – the Blautopf, the Aachtopf and the Wimsener Höhle – are research caves: diving is banned or allowed only with special permission. Mines are private property and show mines are under mining supervision, so you always dive through the owner or the operator, with booking, certification checks and their house rules. The water stays at about 7–8 °C all year.

Facts

Show mines are under mining supervision: Under §129 of the Federal Mining Act (BBergG), most of the operating-plan and supervision rules (§§ 50–62 and 65–74) apply accordingly to show mines and show caves (Besucherbergwerke, Besucherhöhlen). Saxony's mining authority (Sächsisches Oberbergamt) issued a directive on running show mines and show caves (in force since 6 Sept 2009) and lists both the Felsendome Rabenstein and the 'Altes Kalkwerk' Miltitz among Saxon show mines. In practice you never enter a mine on your own: diving runs through the operator under its house rules. (source: gesetze-im-internet.de, revosax.sachsen.de, oba.sachsen.de)
Caves and near-natural galleries are protected biotopes: The Federal Nature Conservation Act (BNatSchG §30(2) no. 5) lists caves and near-natural galleries (Höhlen sowie naturnahe Stollen) among legally protected biotopes; acts that could destroy or significantly damage them are prohibited. Bat protection shapes the seasons: the Nuttlar mine closes in winter for hibernating bats, and the municipality of Grabenstetten issues no Falkensteiner Höhle permits between 1 October and 31 March. (source: gesetze-im-internet.de, xray-mag.com, grabenstetten.de)
Karst spring caves: bans and permits: The town of Blaubeuren has barred divers from the Blautopf since the 1980s after several accidents; only rescue and research groups (e.g. DLRG, the Arbeitsgemeinschaft Blautopf) get special permits. The Aachquelle may be dived only by experienced cave divers with permission, according to the town of Aach. In the Falkensteiner Höhle a police ordinance (in force since 6 April 2018) bans walking and diving beyond the first constriction about 20 m inside unless the municipality grants an exception. The Mühlbachquellhöhle (Dietfurt) is locked and open only for research. Check current status. (source: de.wikipedia.org, aach.de, grabenstetten.de, showcaves.com)
Water temperature: Flooded mines stay cold all year with no thermocline: the Nuttlar operator gives about 7–8 °C, divers report about 8 °C in Miltitz, and 7–8 °C was reported for the Kleinenbremen mine lake. A drysuit, cold-water regulators and solid drysuit skills are expected everywhere; Miltitz asks for logged dives in water below 5 °C. (source: bergwerktauchen.de, taucher.net, travelbook.de, tauchtreffdd.de)
Seasons: Nuttlar is open April to November on Saturdays and Sundays (09:00–18:00). Miltitz is dived only in the winter half-year on announced dates – none from May to July – and slots usually sell out within days. The Felsendome Rabenstein can be dived at any time by prior arrangement. Check current status/terms. (source: bergwerktauchen.de, tauchtreffdd.de, felsendome.de)
Certification and base rules: Operators set their own rules. Nuttlar: guided cavern trial dives from OWD with cold-water protection, two separate regulators, at least two lights, a dive medical and diving-accident insurance (about 50 dives recommended); certified cave divers from a recognised agency get a day ticket, others need a check dive; at least 100 logged cold-water dives, no scooters, no solo diving, check-in/out. Miltitz: AOWD/CMAS** or equivalent, at least 75 dives including two below 5 °C and two night dives, a sports-medical certificate, three lights, at least a double 7-litre with isolator manifold and a 50 m reel; dives follow the rule of thirds, and without a guideline course only the cavern zone to 15 m is allowed. Check current terms. (source: bergwerktauchen.de, tauchtreffdd.de)
Overhead hazards: Mines and caves have no direct way up: silt from clay floors or from touching old mine carts can wipe out visibility in seconds, and passages branch into unlined side galleries. Karst spring caves add strong flow, narrow sumps and sudden flooding after rain or snowmelt – the Falkensteiner Höhle can fill up to its entrance. In February 2021 an experienced cave diver died on a research dive in the Mühlbachquellhöhle after a narrow sump; there is no phone signal underground. (source: xray-mag.com, taucher.net, arge-grabenstetten.de, volksstimme.de)
Emergency: Call 112 first. Diving emergency hotlines listed by GTÜM: DAN Germany/Austria 00800 326 668 783 (00800 DAN NOTRUF), DAN international +39 06 4211 8685 or +39 06 4211 5685; Navy Maritime Medical Institute (Kiel) +49 431 5409 1441; VDST hotline +49 69 800 88 616; aqua med +49 421 240 110 10. Underground there is usually no mobile signal, so agree a surface contact and check-out time with the operator.
Hyperbaric chambers: GTÜM list 1 (emergency centres for diving accidents, as of 1 Jan 2025) includes Halle (University Hospital), Düsseldorf (University Hospital), Gelsenkirchen (Knappschaft), Aachen (HBO-Zentrum Euregio), Wiesbaden (Druckkammerzentren Rhein Main Taunus) and BG Klinikum Murnau. Chambers with guaranteed 24-hour readiness include Ulm (Bundeswehrkrankenhaus, +49 731 17 10 20 55, 30 min notice) and Regensburg; the Überlingen chamber at Helios Spital has limited service. Always phone ahead before transporting a patient. Check current status. (source: gtuem.org)

Season

Best months: Jan, Feb, Mar, Apr, May, Jun, Jul, Aug, Sep, Oct, Nov, Dec
Water temperature: 7–12 °C

Mines and caves: the water stays at a constant temperature all year (typically about 7–12 C depending on the mine), so they can be dived in any season; access is set by the operators (medical certificate, insurance, permits). No exact temperature source was found.

Dive sites (10)

Swabian Jura & Baden-Württemberg

Aachtopf (Aachquelle) – 0–18 m, advanced
Blautopf (TILOS / no diving) – 0–21 m, advanced
Falkensteiner Höhle – advanced
Wimsener Höhle – advanced

Saxony & Ore Mountains

Altes Kalkwerk Miltitz – 0–60 m, advanced
Felsendome Rabenstein – 0–17 m, advanced

NRW, Sauerland & North Hesse

Besucherbergwerk Kleinenbremen – Blaue Lagune – 0–20 m, advanced
Schieferbergwerk Nuttlar – 0–30 m, advanced
Schiefergrube Christine (Willingen) – 0–47 m, advanced

Bavaria – Franconian Jura

Mühlbachquellhöhle (LEZÁRVA / closed) – advanced

Operators (3)

Bergwerktauchen Nuttlar – dive centre, Briloner Straße 48a, 59909 Bestwig (Schieferbergwerk Nuttlar)
Tauchtreff Dresden – dive centre, Dornblüthstraße 19, 01277 Dresden
Tauchschule Sachsenluft (Tauchsport Sachsenluft) – dive centre, Augustusburger Str. 23–25, 09111 Chemnitz

Routes (4)

Mine and cave diving is overhead diving: without cave or mine training, a continuous guideline, the rule of thirds and redundant gear and lights it can be fatal. Every site here can be dived only through the operator or owner, or with an official permit – several are closed or reserved for research teams. Rules, dates and prices change, so check them with the operator or authority before you go. Positions are for orientation only.