Divje jezero
Depth reached by Luigi Casati, about 450 m from the entrance, as reported on the FFS fiche (date of the dive not given).
A karst spring lake in a steep rock amphitheatre in the Idrijca valley near Idrija whose flooded shaft has been explored to 160 m. After several fatal accidents, diving in the spring is reported to be prohibited.
Divje jezero, the 'Wild Lake', is a deep spring pool about 60 by 30 m set in a dark, cliff-walled cirque in the Idrijca valley south of Idrija. The FFS fiche describes it as a protected natural site that remains freely accessible to visitors.
At the bottom of a cobble slope cluttered with tree trunks, the flooded gallery begins at about 15 m. The conduit, of tectonic origin, descends through a chaotic gallery to about 60 m, where a terminal shaft bends into an inclined tube that divers have followed to 160 m.
Slovenian divers explored the cave in stages from 1957, reaching 38 m in 1969, 50 m in 1972 and 83 m in 1981. Tomo Vrhovec passed 100 m in 1995 and reached about 135 m in 2000; Olivier Isler reached 122 m in 1996; and the Italian diver Luigi Casati reached 160 m about 450 m from the entrance, with eight hours of decompression in very cold water. Three divers have died in the spring according to a report quoted on the fiche.
The fiche states that, following these fatal accidents, dives in the spring are now prohibited. Water temperature is given as about 6 to 7 °C, and divers have reported poor visibility.
Water, flow and flooding
A powerful spring draining depressions on the higher massifs to the south; the FFS fiche mentions a reported hydrological link with the Postojna region.
Why it matters
One of Slovenia's best-known deep karst springs and a site of deep exploration dives since 1957.
Conditions
Very cold water; poor visibility reported by explorers (about 3 m on one 1996 dive).
Typical ranges from published sources, not current conditions.
Survey and exploration history
| 1957 | B. Rupnik and M. Straus make the first dive and find a flooded gallery at the bottom of the lake. [1] |
| 1981 | P. Krivic and A. Praprotnik reach 200 m from the entrance at 83 m depth. [1] |
| 1996-02 | Olivier Isler reaches 122 m depth, 335 m from the entrance. [1] |
| 2000 | Tomo Vrhovec reaches about 135 m. [1] |
Entrances and dive sites
One entrance, the spring lake.
Every fact on this page, with its source (6)
| Fact | Status | Source |
|---|---|---|
| Luigi Casati reached 160 m depth about 450 m from the entrance.Quoted report on the fiche; dive date not given. | Reported | [1] |
| The lake measures about 60 x 30 m and the gallery starts at 15 m at the base of a cobble slope. | Verified | [1] |
| Exploration reached 38 m (1969), 50 m (1972), 83 m (1981), 112 m (1995), 122 m (1996) and about 135 m (2000). | Verified | [1] |
| Water temperature is given as 7 °C on the fiche and 6 °C in a quoted report. | Verified | [1] |
| Following fatal accidents, dives in the spring are prohibited; the site is protected but freely accessible.Fiche undated; the legal basis and current status were not confirmed with Slovenian authorities. | May be out of date | [1] |
| Diving is prohibited according to the fiche. | May be out of date | [1] |
Verified: stated by an official or primary source we opened. Reported: from a secondary source only. Sources conflict: the note gives both versions. May be out of date: the newest source we found is old.
Written in our own words from the sources above. Report a correction