DATELINE :- 2nd August 2000
RESSEL ADVANCE
Cave divers a step beyond in Ressel
Top British cave-divers Ric Stanton and Jason Mallinson have returned to the challenging Ressel cave system in France's Dordogne region and laid a further 770m of line from the point they reached last year.
Their penetration brings the total distance covered to 4600m from the cave system's entrance. Of that, 4070m has been traversed under water, the remainder representing air pockets in proximity to four separate sumps.
"From our last point, just beyond sump five, we continued through an underwater section some 12m across and 8m high," Ric Stanton told Diver. "We were finally stopped by a boulder choke set right across the passage."
The choke, said Stanton, is passable but will pose a severe challenge in "streamlining" if further progress is to be made. "We're going to take a break from Ressel and do some other things while we think about it," he said.
In the system for two days, the men, both experienced rebreather-users, departed from practice on their previous expedition by using rebreathers, a Buddy Inspiration and a Mk IV Cis-Lunar, with VR3 computers to manage their decompression schedules.
The rebreathers did not reduce gear carried because open-circuit back-systems, with two 20 litre cylinders each, still had to be carried. But the rebreathers increased diving time capacity and cut back on deco times. "In sump one, we were decompressing for about four hours with the rebreathers, compared to five hours on open circuit last time around."
Sleeping in a cave between sumps two and three, the men found the chamber a little low on oxygen. "When it came to cooking our freeze-dried food, combined with natural cave water, we had to use nitrox gas to help our matches light. The cooker was OK once it had warmed up." Sleeping bags were not carried, as the caves are a reasonably warm 12-13¡C.
The men's only worry as they entered the system was that it started to rain. "We knew it was not going to deluge and were confident that levels would not rise to a threatening level, so went ahead with the penetration," said Stanton. "But while we were in there, water levels rose by about 20cm and a bit of a current developed. We coped OK and, of course, had the current with us for the journey back."