South Wales Caves: Blog Post Porth Yr Ogof by Rich Walker

Chris in the Upper Cave Water Chamber
Porth Yr Ogof

Today we set out to dive Porth yr Ogof with a list of jobs as long as your arm. We wanted to finish a section of the survey at the end of the sump where it surfaces into Upper Cave Water Chamber. Also, we were not aware of any photographs having been taken in this dry section beyond the sump, so that was on the list. We needed to identify a photo site for regular photo readings for Project Baseline. The line had a few rough areas on the way in and these needed to be fixed too. So it was looking like a busy day out.

We arrived at the Porth yr Ogof car park at about 11am to find the usual 3-4 minibuses full of young children on their first trip underground. Their leaders used us as examples in their briefings - "Those crazy people over there are going diving in the cave - but don't worry we're not going where they are".
It was perishingly cold with snow blowing in the air and a sharp wind to keen the mind. We put our suits on quickly and elected to run down to the cave in one hit, rather than the usual leisurely ferrying of the heavy equipment.
We did our gear checks and went over the plan just outside the entrance and one-by-one entered the cave. It's too small to go in at the same time, so we met up in a small airbell just inside the entrance and headed into the cave.
Jarvist did a great job of tidying up the line on the way in, Christine followed, and I took the position at the back of the team meaning I got to have a good look around for photo sites. Our aim was to move as quickly as possible through this section, as the dive to the end is just about on thirds, so we were limited in what we could do here, but even so, we got to fourways airbell, about 30m from the end well inside or gas limits, so all was good.
On the way in, the visibility was about 3-4m, medium for this cave. We saw several trout, a couple of bullheads and one or two caddis fly larvae. I've never seen those in here before so that will be something to keep an eye on in the future. I always wonder how the fish get into the cave - maybe from Church sinks or maybe they swim upstream. It would be interesting to find out though.

Large trout in Porth Yr Ogof

The flow was not especially strong, but you did need to work a little to make progress. Nothing like you might experience in Florida, for example, but flowing nonetheless. We reached the end of the sump after about 30 minutes, it finishing up in an upward running bedding plane which was a little bit low, but not what I'd call a squeeze at all. Visibility was pretty much zero though, as two others had gone through before me.

Surfacing in the Upper Cave Water Chamber was a first for me, so I was keen to have a look around here. I was pleased to have made the trip as the cave, after a short climb up, becomes a high level scalloped and decorated passage. A short walk along here leads to a static sump, crystal clear water with a tempting line running into it. It is possible to bypass this, but it seems nice enough to me to dive. Next time, maybe.

Rich looks into sump 8, Porth Yr Ogof

Christine began setting up the photo shoot with the tripod, lighting and other paraphernalia that comes with photo trips. We took shots of divers peering into the sump, standing in the passageway and climbing up the rocks from the sump too. The results were very impressive, and well worth the trip.

Jarvist in Upper Cave Water Chamber

After about an hour beyond the sump, we decided to pack up and head home, as we were getting a bit chilly and hungry. We waited until we were all pretty much ready to leave, and I headed off first. I hung around for a short while at fourways junction (which only has threeways, for some reason), gathered the team again and headed back to the exit. The outbound trip took less than ten minutes, giving you an idea of the flow in the cave helping you out. At Cwmbran junction, I took the time to have a look up into the passage. This is supposed to be an alternative exit from the cave, but is often choked with tree branches. High up in the roof, I could see that there was a gap, and I swam up into it. There was a light flow coming down the passage, blowing all sorts of debris back towards Jarvist, but it looked like the way might be cleared without too much trouble. Either way, the junction itself looks like a perfect site for our regular photograph. Maybe another job for the next visit. We headed back to Tradesman's entrance and climbed out, about 100 minutes after we'd set off. A great dive!