Post date: Jul 30, 2009 12:46:06 PM

Cavers - Gaelan Elliffe, Alasdair Kennedy; non-caver - Tony Furnell

The plan was to dive the downstream sump, more in hope than in expectation of any underwater extension of more than 1 m.

After carrying Artur's bottles in and out of Prod's Pot on Saturday and carrying our bottles out of Aghinrawn on Monday, Gaelan was clearly in bottle carrying mode so i thought to resurrect something from the weekend trip to Marlbank and dive in Pollthanarees downstream sump, helped by Gaelan after some persuasion. This was something i had been looking at for a while, but we'd never got round to visiting it. There is no record of any previous dive in the sump, and since the downstream end of Pollthanarees is right on the edge of the Mastodon shakehole it could reasonably be predicted that the Sruh Croppa was sumping straight into boulders. Still, curiosity meant that it needed checked out, more-so with the new-found Northern Way link and a better understanding of the boulders in the shakehole, which i'd pushed from the Northern Way side.

After a bit of faff in the morning i finally got two bags packed with 7L and 3L bottles and the rest, and Gaelan and i set off under the guidance of Tony, who had elected to do some surface speleology. As we were entering the cave a heavy rain shower set in, looking like it would persist for some time. The entrance series was easier than i was expecting, and we made good time down to the noisy streamway. Fresh foam on the roof spoke of a recent flood and we were wary of the water levels. It all looked normal though at the present so I took a quick romp down to the sump to see how things looked. Returning for Gaelan and the bags a 2 minute crouching crawl brought us to a large sandy beach before the sump chamber which made a comfortable dive base.

From the final sump chamber it seemed that the way on was somewhere along the left wall, so i made a good belay on a convenient spike. After some floundering in the stream i found an alcove and fumbled around it before finding the sump proper. This stayed shallow (max. depth 2 m), with a sandy, gravelly floor, and was surprisingly spacious. With all the rain the vis was pretty poor, although the stringy organic debris in the water gave me some indication of the flow, but it was very slow (either i was out of the main flow or the sump is quite wide - i suspect the latter). Moving along the left wall it soon became large boulders, and a quick check up confirmed that the roof was the same. However there was no small stuff apparent in the gaps so with a little less trepidation i progressed some more. At the 15 m mark on the line the flow, still slow, was disappearing into an awkward gap in boulders, but it still felt wide to the right so i squeezed up 1 m over a gravel bank into the roof boulders, reaching 0.9 m and hearing bubbles surfacing. I couldn't find anywhere large enough to fit through although it seemed to widen out above. After some more searching on the right i returned to the final belay at 15 m and cut the line, doing a quick survey on the way out. General trend is south-east.

After returning to Gaelan on the beach we both separated again to check out a couple of side passages, Gaelan opting for a muddy rift on the left leading off the beach while i choose the left branching canal. This closed down to the water but i could feel some way on. Taking the line i swam a short distance before hitting boulders and managed to surface in a constricted air-space. I could see a tight way on between two boulders with 3 or 4 m of passage visible but it was too tight and spikey to squeeze in a drysuit. I tied off the line and returned. I think in lower water this short sump would be a duck, and the bouldery continuation may be on the survey (i couldn't remember when i checked the survey afterwards if i had turned the slight bend or if the 'sump' was on the bend); the description says this passage ends in boulders.

Gaelan returned from his side passage while i dekitted and then i went to support him while he grovelled in some loose boulders at the end. When we returned to his previous point there was a water splash coming from the ceiling and it all looked a bit shoogly. Gaelan starting pushing an upward squeeze in boulders, but after Bloody Sunday in Aghinrawn we weren't so keen to force it. This must be the way to the high level passage. When we got back to the mainstream the water had risen by 1.5-2 inches or so in the few minutes we were away so we figured that it was best to get out while we were ahead, and quickly repacked and left.

Al