Czechia – Bohemia: Quarries & Lakes

Bohemia has no sea, but Czech divers have turned its flooded quarries into a dense network of inland dive sites. Most are run by a dive base or club that charges a day fee and checks your certification: Borek with its Ikarus bus at 31 m, Srní near Hlinsko with a bus, an aircraft and big catfish, Leštinka, Bořená Hora with its helicopter wreck, and Horní Cerekev. The Vltava reservoirs offer deeper, darker dives, the best known being the drowned church of Těchnice in the Orlík reservoir at 26–42 m. In the north-west, the former brown-coal pits of Most and Milada are being turned into large lakes. Some quarries are closed by their owners or the mining authority; these are marked.

Facts

• Water temperature at depth: Czech quarries and reservoirs are cold: typically 2-6 °C at depth year-round in the database logs, with surface up to about 20 °C in summer (e.g. Hrádek 19 °C, Slapy 3-12 °C, Borek 2-6 °C). A drysuit is recommended.
• Access model for quarries: Most flooded quarries are private land: access is via the operator's dive base with an entry/dive fee (typically 100-350 CZK per day) and proof of certification; unmanaged reservoir sites (Slapy, Orlík, Lipno, Milada, Most) are listed as free and open.
• Mining-authority entry bans: Entry into some active or abandoned quarries is banned and fined by the mining authority (reported ~15,000 CZK at Velká Amerika, where patrols were reinforced).
• Cave rescue: Cave Rescue Service of the Czech Speleological Society (SZS ČSS), a voluntary body founded 1982, part of the Integrated Rescue System, with Bohemian and Moravian units. In an emergency call 112. ČSS secretariat (not an emergency line): sekretariat@speleo.cz, +420 722 651 110.
• Hyperbaric chamber: Městská nemocnice Ostrava runs a Centre of Hyperbaric Medicine (new chamber from 2024; the hospital's main phone is 596 191 111 or 556 541 111, mnof@mnof.cz, Nemocniční 898/20a, Ostrava). Emergency availability of the chamber is not stated on the page: confirm by phone. A chamber at Nemocnice České Budějovice (opened 2020) is reported in a hospital press release (not fetched).

Season

• Best months: May, Jun, Jul, Aug, Sep, Oct
• Acceptable: Mar, Apr, Nov
• Poor: Dec, Jan, Feb
• Water temperature: 2–24 °C

Quarries with a base can be open year-round, including ice diving in winter. In summer the surface reaches 20–24 °C, but below the thermocline at 7–8 m it is 3–11 °C and 2–6 °C at depth. Borek has its best visibility under ice in winter; in the reservoirs visibility is often only 1–3 m in late summer.

Dive sites (17)

North & West Bohemia

• Jezero Barbora (Oldřichov u Teplic) – 0–40 m, intermediate
• Jezero Milada – PM3 Trmice – 0–25 m, beginner
• Jezero Most (Ležáky) – 0–71 m, intermediate
• Lomeček (Starý Klíčov) – Atlantis – 0–10 m, beginner

South Bohemia & Vysočina

• Lipno – Frymburk (flooded cemetery) – 0–10 m, beginner
• Lom Horní Cerekev – 0–22 m, beginner
• Lom Slověnický mlýn (COP) – 0–28 m, beginner

East Bohemia & Vysočina

• Lom Borek – 0–34 m, intermediate
• Lom Leštinka – 0–26 m, beginner
• Lom Srní (Hlinsko) – 0–33 m, beginner
• Pískovna Hrádek – 0–10 m, beginner

Central Bohemia & Prague

• Lom Bořená Hora – 0–23 m, beginner
• Lom Kosov (TILOS / diving officially prohibited) – 0–6 m, beginner
• Lom Velká Amerika (TILOS a belépés / entry banned) – 0–11 m, intermediate
• Lom Vševily – 0–20 m, intermediate
• Orlická přehrada – kostel sv. Štěpána, Těchnice – 0–58 m, advanced
• Slapská přehrada – hráz (přístaviště) – 0–56 m, advanced

Operators (8)

• POTYA water-sports centre (SSI) - Bořená Hora – dive centre, Bořená Hora 5, 264 01 Štětkovice
• Divers Direct (Divers.cz), Prague – dive centre, Čs. armády 13, Praha 6 - Dejvice
• ALEA Divers - centrum potápění, Prague – dive centre, Kamýcká 131/10, Praha 6 - Suchdol
• KWS Diving, České Budějovice – dive centre, Lidická tř. 1277/252, 370 07 České Budějovice
• Divepark Leštinka – dive centre, Kovárna, Leštinka near Skuteč
• Boržík family dive base - Leštinka – dive centre, Leštinka near Skuteč
• Potápěčský spolek Pelhřimov (Lom Horní Cerekev) – club, Lom Horní Cerekev, 394 03 Horní Cerekev
• TOP DIVE s.r.o. – Lom Srní – dive centre, Lom Srní 1706, 539 01 Hlinsko

Czech quarries are cold and often dark: below the thermocline the water stays at 2–6 °C all year, so a drysuit, cold-water regulators and good buoyancy are essential. Fees, opening times and operators change (Borek changed operator in 2026); check with the base before you travel. Sites marked unverified rely on diver databases only. Positions marked approximate are for orientation only.