Owing to light failure, no progress was made.
Previous exploration: NL.16:19, where it is referred to as Yew Cogar "Two". The cave consists of some 30 ft. of passage leading to a sump of ample dimensions. After 10 ft., mostly with unusable air space, a small air bell is reached with complete sump beyond. The submerged passage is some five feet high and two feet wide and after 100 ft an air bell was reached with two ways leading on. To the left a sump continued on but in smaller dimensions, and to the right an awkward narrow canal passage with about a foot of air space could be seen to continue for at least 10 ft. to a bend. Excessive drag on the base fed line made the diver decide to call it a day.
Aim: to push on beyond the previous limit. From the previous limit the sump left hand branch was taken and a small tube followed to a sharp right hand bend after only a few feet. About ten feet further on the passage still retained its body sized dimensions and began to dip sharply downwards, so the diver returned to the air bell and proceeded to explore the easier looking right hand branch. This was found to be a fifty foot long canal through which line was laid, because of the awkward nature of the passage and the difficulty of making adequate use of the air space. At the end of the canal, a low dry bedding led forwards but to the left, underwater, a more easily enterable body size tube was followed for 10 ft to a rift type air bell with deep flooded joint below. A bedding cave leading back above water level was noted, which most probably connects back to the low bedding noted above. The rift was descended for 10 ft and was found to be narrow and awkward. At that point the diver decided he'd had enough thrutching about for one day and returned to base.
Previous exploration: NL 15:7, NL 16:19, NL 30:16, NL 31:20, NL 33:12 & 13 with summary.
The line in sump 1 was reinstated but the sump 2 line was found to have disappeared.
The divers proceeded to sump 2 and a new line was laid. The line in Sump 3 was found to be in usable condition but due to high water levels and a bad weather forecast the explorers had to be satisfied with proceeding only as far as the end of Sump 3.
Previous exploration: NLS. 15:7, 16:19, 30:16, 31:20, 33:12 (with summary of progress) and 52:26
Aim: to check the line in sump 4 and if possible proceed beyond the previous limit in the upstream sump.
Both divers reached the end of sump 3 without undue difficulty and R.J.S's. gear was taken to Sump 4 through the awkward Bed of Nails Crawl. It was decided to lay completely new line, for fear that the old had been washed back and become tangled. R.J.S. thus began laying new line from the start of the sump and 500 feet of new line was put in place, passing the previous limit by 50 ft. The passage continues much as before with no air space in sight as yet. The old line was exactly as left nearly five years ago but the old line reel was nevertheless cut free and the line pulled out from base to avoid confusion. The new line is securely belayed to a lead block and cannot be washed back, barring breakage of course.
Previous exploration, see NL 52:26.
Aim: to push on in Sump 4.
Both divers proceeded to the end of Sump 3 and this time two sets of gear were carried to Sump 4. R.J.S. dived first with a 94.5 m line reel followed closely by J.T.G. Tieing on at the previous limit, a further 15 m of line was laid in a small tubular passage to an air bell with deep water and a tiny inlet at roof level. Having been joined by J,T.G. in the new air bell, R.J.S. then proceeded to explore the underwater continuation. After a further 18 m of progress, a very low section, with much mud and shingle present was reached. The diver could find no way round this and on his way back to the air bell no alternative possibility was found. Back at the air bell, J.T.G. had looked at the inlet and found it to be impenetrable and after a discussion both divers decided to return. On the way back, two possible continuations were noted beyond the 91 m underwater chamber. Sump 4 is 167.6 m long to the air bell.
Aim: to search the right hand side beyond the 91 m. chamber in Sump 4.
As before both divers entered the final sump with R.J.S. leading and carrying a jump line. From the bottom of the 91 m chamber the right hand wall was followed as far as the airbell at 167.6 m and the two continuations noted on the previous dive were explored for short distances, Both were found to be smaller than the lined route and may just be low beddings off the main tube. R.J.S. then decided to have a second attempt at the low section beyond the air bell. Having attached the jump line, the diver pushed on for only 3 more metres past an awkward right hand bend to where the passage became impossibly low. The mud stirred up did not clear and the poor visibility at the end did not subsequently appear at the air bell, indicating that the flow has been lost. R.J.S. then joined J.T.G. in the air bell and it was decided to search the 91m chamber again. R.J.S. did this on the way out using the jump line, but only confirmed his observations of 13th July 1974 (NL 33:13) when the only way out of the chamber was found to be at floor level. This sump is proving more awkward than expected.
Collected weights left at start of upstream sumps and then went to have a look at the sump downstream of Jetsam Chamber. An easy 9 m dive led to a small chamber with daylight streaming in through a choke in the roof. This represents a flood resurgence about a third of the way from the cave to the rising cave. The sump continued but was not attempted because of a shortage of base fed line.
Aim: to dive main downstream sump.
The sump drops down a 1.5 m pot to a small bedding. This was pushed for 3 m before it became too tight. Little prospect of further progress, even with "lightweight" gear.