Réseau de l'Ouysse (Cabouy – Pou Meyssen)

The flooded underground course of the river Ouysse below the Causse de Gramat, entered at the Cabouy resurgence near Rocamadour and at the Pou Meyssen shaft 800 m upstream. Its first sump is about 2,400 m long.

The Ouysse flows largely underground beneath the Causse de Gramat and reappears at the Cabouy resurgence at the foot of Rocamadour, a few kilometres before it joins the Dordogne. Its size and flow made it one of the first objectives of French cave diving.

From the Cabouy pool divers descend quickly to a low point near 30 m, after which the floor rises gently over about 800 m to around 11 m depth, where the Pou Meyssen shaft provides a second way into the river. Beyond Pou Meyssen the passage dips again to about 30 m and then climbs over more than a kilometre to surface, roughly 1,950 m from Cabouy, in a lake about 400 m long; the second sump starts a few metres beyond it.

Between 2011 and 2014 two FFESSM divers, Franck Gentili and Renaud Cabanne, replaced the worn and broken guideline (the continuous line divers follow back to the exit) along the whole first sump, removed more than 3,000 m of old line, and marked the new line every 50 m with distances from Cabouy. Their account stresses that seasonal floods regularly break lines in this cave.

The traverse from Cabouy to Pou Meyssen was first made by Claude Touloumdjian, and a Franco-Swiss team passed the 1,200 m sump beyond in the early 1980s, according to the same account.

The Ouysse is a major river of the northern Lot that runs under the Causse de Gramat and resurges at Cabouy. Violent seasonal floods are reported to tear out guidelines. At Pou Meyssen the water level varies with the seasons and the small pool silts up immediately when divers enter.

One of the historic objectives of French cave diving and a long, relatively shallow river cave regularly used by visiting cave divers; its first sump was fully re-lined by volunteer divers in 2011-2014.

Typical values only. Floods are seasonal and violent; Divernet describes zero visibility through the silty approach at Cabouy, improving greatly inside the cave, and the Subaqua account says the Pou Meyssen pool clouds up as soon as divers enter.

نطاقات اعتيادية من مصادر منشورة، لا ظروف آنية.

Two diveable entrances are documented: the Cabouy resurgence pool and the Pou Meyssen shaft about 800 m upstream (underground distance).