Emergence du Ressel
par John Volanthen & Rick Stanton
|Emergence du Ressel
divers Rick Stanton & John Volanthen
Both divers passed Sumps 1 & 2 in convoy, testing various configurations for use in Spain later in the year. Lines were found to be continuous and in excellent condition. The crawl in the air space just before the bivouac chamber appears to have been dug out somewhat, allowing easy passage. On arriving in the bivouac chamber, 3 loads of equipment each were carried to Sump 3 before the divers settled down for the night. The air in the chamber was bad, with high Co2 and low O2, requiring JV to light the gas stove in a plastic bag of nitrox.
The divers left back mounted rebreathers for the return through S1 & S2
and went forward using side mount rebreathers, scooters and open circuit
bailout (worryingly JV had less gas than RS). The second dry section
Both divers packed up camp and made an uneventful exit, to RS's amusement JV once again proved unable to drive his ride on scooter down some of the big shafts! Surfacing at about 11am, both divers scootered down the river to arrive at the campsite in Marchillac.
The sump mapper was used to survey sump 1 to allow a comparison to be made with the existing high grade survey. The results were promising, however whilst the bearings are accurate it appears very difficult to get accurate distance results either swimming or on a ride on scooter due to flow turbulence and proximity to the diver. The answer is to use a tow behind scooter where possible - modifications are being considered.
Whilst there is a lot of information regarding the Emergence du Ressel,
there is very little description of the cave beyond sump 1. The
informaton below is provided to give anyone intending to visit the
farther reaches of the cave some idea of what to expect:
On ascending a series of shafts at the far side of S1, a shaft rising to -12m is reached. On the left, in the roof is a passage that takes most of the flow in normal conditions. This is the bypass to reach S2 without crossing dry land (via Lac T). This passage is not obvious, the line into it is often broken. If you follow the obvious way, you will almost certainly surface in the salle des blocks.
On surfacing at lac T, turning right (south) submerges rapidly into S2
(max depth about 12m). After about 200m a junction is reached. Turning
right surfaces in a canal that leads to the Salle des blocks. Turning
left (North West) following the main line upstream leads into a larger
tunnel "The Metro", the passage surfaces after about 100m where the
water flows over large blocks. A 10M long channel has now been dug
through these to allow crawling progress without de kitting. This air
space was not counted by the original explorers, so Sump 2 ends after a
further shallow dive of about 80m at a boulder slope leading up into the
bivouac chamber. This chamber is about 50m long and 10m high. The ground
here is broken and sharp, care is needed when walking in drysuits. The
air in this chamber can be bad - high Co2 and low O2, it seems to be
worst at the water level on the S2 side, improving as the rocks are
The lake on the far side of the chamber provides a spacious area to gear
up. 50 meters of canal is passed, before encountering S3. This is very
short (5m) and can be missed if scootering mid water. a further 300 -
400 meters of canal (the lac long) leads to Sump4, which is 240m long
and shallow. This finishes at another boulder pile in a small sump pool.
Turning right (upstream / North) after 300m a maximum depth of 18m is
reached before a boulder slope can be followed to surface. At the base
of the slope, low and on the left, 50m of ongoing smaller passage in a
NW direction leads to the terminal upstream boulder choke found by Rick
Stanton and Jason Mallinson. Back at the 1000m T junction, turning left
(downstream / South west) the large fossil passage continues in a South
Westerly direction for about 900m, where it is possible to surface in
an off route air bell. This ongoing passage is generally large with a