After 35 years of cave exploration in the Picos de Europa, OUCC's work has entered a new and exciting phase where we are beginning to see parts of the drainage to the Culiembro resurgence link together. In 1995 a major stream was reached at -640m at the bottom of an arduous cave called C3, clearly an important piece of the drainage puzzle, and dye tracing showed it was part of the Culiembro catchment. Progress downstream was soon halted by a lake, explored by inflatable dingy and thought to be a sump pool.
The initial aim for 96 was to try and bypass the lake. But, as we didn't have a strong enough team to take on a project the size of C3, our alternative plan was to find an easier route into the streamway. Our targets were two caves in the catchment of upstream C3. Polifemo, a Spanish group, invited us to descend one of their discoveries, Torca del Vasco, which could provide a much lower entrance. Our second target, C4, was first explored in 82, as was C3. Several leads at the bottom were all described as too tight', but cavers were fatter in those days.
Over the years we have logged more than 300 entrances, but the location of many has been forgotten. John Pybus led a project to relocate and link a large number of entrances with a surface survey, now plotted on a 1:10,000 topographical map. This will help us build a picture of the relationships between the caves in the Culiembro catchment and focus the search for the missing parts of the drainage system.
As an alternative means of fixing entrance coordinates we conducted trials with a GPS but concluded that it was much less accurate than stated and no substitute for a surface survey.
Having rigged Vasco in 2 days we found that the Spanish were right - the meander at the bottom of the cave was impenetrable - but a hole near the base of the last pitch bypassed it. Meanwhile C4 was rigged to the 82 limit and the way on found by pulling out boulders in the rift. During the next 3 weeks the caves got deeper every day, the highlight being the discovery of The Monster' in C4, a 76m freehang with an inversion layer forming clouds halfway down the shaft. Eventually a horizontal streamway was reached. No one in the team had been to the bottom of C3 before, but they knew they had made the connection when they found the dingy still securely moored by the lake.
After 4 weeks of the 7 week expedition only 6 cavers remained, who had to work extremely hard finishing the survey, taking photographs, paddling in the dingy, exploring upstream of the C4 inlet, and beginning to derig - all in the same trip! Having reached the main streamway, we wanted to carry out a dye trace from Vasco, to see if it did indeed flow to C3, but we didn't have the manpower.
After derigging C4 attention turned to Vasco. A series of muddy phreatic passages all ended depressingly at muddy pools. Two other branches to the cave were found, but the cave was eventually declared finished at -375m when twin clear blue sump pools were reached.
In addition to completing the exploration of 2 caves, we achieved our main objective: an easier route into the C3 streamway. Despite being nearly as deep at -584m, it is a significantly easier route, and will aid the future exploration of the system.