Data: Porth yr Ogof 26/03/2013 Richard Walker, Dived

Your name:	Richard Walker	Observation date:	26th March 2013
Site Visited	Porth yr Ogof

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Church Sinks Observations
The river water was Flowing under the bridge
Church sinks flora: Moss
Church sinks fauna: None noted
Church sinks water temperature: Not recorded
General Church Sinks observations: Large tree root stuck on bridge support.

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Top Entrance Observations
Accessible by walking up the riverbed?: Yes
Top Entrance Flora: Not visited
Top Entrance fauna: Not visited
Top Entrance water temperature: Not recorded
Top Entrance general observations: Not visited
Dives done into Top Entrance?: No

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Top Entrance Dive Log
Top Underwater Visibility:
Top Water flow:
Tope entrance underwater fauna:
Top Entrance other observations:

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Tradesman's Entrance Observations
Tradesman's flora: Moss Ferns Harts Tongue ferns
Tradesman's fauna: None noted
Tradesman's water temperature: 4 degrees C
Tradesman's water level: 40cm below edge of ledge (estimate)
Did you dive at Tradesman's Entrance?: Yes

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Tradesman's underwater visibility: Medium
Tradesman's water flow: Medium
Tradesman's underwater fauna: Large trout x 6, all pale in colour Bullheads Caddis fly larvae
Tradesman's general observations: Tin can, large green plastic bag - both at Cwmbran junction. Belays tidied, survey of Cobbets Loop to UCWC completed. Photographs in dry passage in UCWC

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Main Entrance Observations
Main Entrance flora: Moss Ivy Harts tongue ferns Other 'fern'
Main Entrance fauna: None noted
Main Entrance water temperature: Not recorded
Main Entrance general observations: Clear water, flowing gently. Wellies gone from pool. Icicles in entrance roof.

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Resurgence Observations
Resurgence flora: Not visited
Resurgence fauna: Not visited
Resurgence water temperature: Not visited
General resurgence observations: Not visited

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Little Neath River Cave Observations
LNRC Observations:

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Final Observations
General Observations: Birds and squirrel in car park. Several groups of cavers. Some litter on path collected.

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!

Rich in Upper Cave Water Chamber
Photo Chris Grosart

Porth yr Ogof Blog Post. A very British day out....

Chris kits up at Top Entrance
Photo Steve Thomas

Following our morning's efforts, we were doing well and took a spot of lunch in the car park at Porth Yr Ogof.
It was bitterly cold with excruciating gusts. Getting changed was a masterclass in speed and efficiency, exposing the least amount of flesh possible.
We set up the compressor and it ran happily, re-filling our 7 litre cylinders for the afternoon.
We changed into dry clothes and put our undersuits on the van heater to dry of a bit. Wrapped in duvet jackets, fleece hats, gloves, neck warmers and still shivering, we unpacked our lunch.

Jarvist sets off into Top Entrance
Photo Steve Thomas

First, the quiche I had been looking forward to had frozen solid. The sandwiches had made it unscathed though. Rich shoveled down a pasty and Jarvist ate some vegetables or something. I always wonder how vegetarians survive the winter...anyway...
There were a few school groups having their first underground experiences in the main 'dry' part of the cave. The water was 4 degrees centigrade and they looked far from warm when they emerged, but spirits were not dampened.

Cylinders filled, divers fed, our next objective was to re-line Cobbets Loop, which was in dire need of attention on my last visit. The line was followable, but one line soon became three - loose and floaty and part buried. The objective was for Jarvist and I to enter Top Entrance and dive the short distance to the start of Cobbets Loop at Fourways junction (which is inaptly named as it actually only has 3 exits....but anyway....).

Rich was superfluous to requirement, much to his delight and he helped carry our gear up the river bed to Top entrance, which is a small hole in the riverbank which after a few metres drops into a muddy looking sump pool.

Jarvist and I kitted up while Rich hopped around with wet feet, having left his wellies at the caving hut....
As we were getting our gear together, a chap appeared on the far river bank with a camera bag.
He called over to us "Are you diving?"
"Yes" I replied.
"Well I'm very sorry, but diving's not allowed here" in a very convincing Welsh-ish accent.
I paused and wondered for a moment if it was Steve Thomas, as it looked a bit like him and we had been conversing on Facebook for a while but not actually met. He had been involved in a lot of exploration in a nearby cave called Ogof Ffynnon Ddu with my CDG mentor, Clive Westlake.
Still unsure, I replied, "Er, yes we are..."
Quite possibly thinking I was a bit dumb, he began laughing and introduced himself as Steve. But not in person just yet as he too had forgotten his wellies!
He popped back to not find them and returned to take some photos of Jarvist and I getting into the sump pool.



Jarvist sets off into the sump with line reel
Photo Steve Thomas

Entering the pool is best done in reverse. It is steeply downhill in zero visibility in a body sized tube.

The first obstacle encountered is a squeeze, with back and front pressed up against the floor and the roof. Jarvist went first and was heard shifting some cobbles around before his bubbles stopped coming, so I knew it was Ok for me to get in. He had very kindly had a good go at digging the squeeze a bit bigger for me and I went through without even touching the roof.

I met up with him at the Fourways junction and he was tying the new line into the large iron railway shoe, which acts as a significant belay point.
Jarvist did a good job of laying thick, heavy duty sinking plastic line through the elegant but not large passage. I bumbled along behind surveying, to get more accurate data on this part of the cave, including left, right and up shots with the sonar device.



Chris backs into Top Entrance sump
Photo Steve Thomas

We negotiated the low bedding plane before surfacing in Upper Cave Water Chamber - a handsome dry section of passage which I was keen to photograph the next day.
We tied the line off to a solid belay - the old line, worryingly, came away from its belay as Jarvist surfaced, confirming that it had had its day and needed to come out.
Luckily I had loaded just the right amount of line onto the reel, so empty reel in hand, Jarvist set about reeling in the old line while I went ahead chopping away snoopies, old bits of tatt and gathering it up and stuffing it in a small caving tackle bag to transport it out of the cave.



Chris emerges from Top Entrance
Photo Steve Thomas

Job done, we surfaced in Top entrance and Rich and Steve helped us carry in one journey back to the van.
We headed back to the caving hut which was just as cold inside as it was outside and the log burner seemed to be very good at burning wood - but not a lot else. I stood in a very hot shower for ages just to get warm - and we ate dinner still in our duvet jackets and fleece hats.
Fortunately, although the hut doesn't have heating, it does have wifi - so we pre-occupied ourselves with food and internet and planned the next days diving.

Another cold night.......

Porth Yr Ogof Blog Post 25th March 2013

Fortunately, the weather was pretty much perfect for our Project Baseline dives today.

Well....when I say perfect, the underwater conditions were average, little bit of current, OK visibility and 4 degrees centigrade. Topside however, was a biting wind and had most of us moaning about it even before we started to get changed - despite bing wrapped up in cosy down jackets.

We figured it would be warmer in the water....

The objectives of todays PB dives were:

• Locate a good 'stake in the sand' photo point, which would be easily recognisable and easy to access, to make a continuing record of the cave. We thought that the top of the 'Pot' about 70m underwater from the Tradesmans Entrance.  
• Run visibility trials using a secchi disc and a variety of light sources, one by one and record the visibility readings. A tape measure would be used for accuracy.
• Patch up the line which had begun to wear through at a rub point at the top of the 'pot'.
• Enter through Top entrance in the afternoon and re-line Cobbets Loop, which leads to Upper Cave Water Chamber.
• Survey from 'Fourways' at a major toe off (iron railway shoe) to UCWC.
• Film/photograph any underwater fauna, specifically trout.

We managed to achieve all of the above despite blood curdling cold. I had expected the water temperature to be a chilly 6 degrees so we all wore drysuits. To our astonishment, it was actually 4 degrees centigrade!!

I was quite proud of myself in 3mm gloves!Dive 1 was to introduce Jarvist Frost to the cave and we dived upstream from Tradesmans, noting some litter along the way. Also noted were about 6 trout, most of them blind and white in colour.

I filmed these and took some screen shots. We arrived at the pot to realise that my failing memory had forgotten that I had already fixed the rub point just over a year ago, so it saved Jarvist a job at least.

He then had the unenviable task of holding up a large, floppy laminated secchi disc and the end of a tape measure, whilst jamming himself across the passage to stop the up-current from taking him away, while Rich and I measured the visibility using various torches, ranging from our helmet mounted 'Rude Nora' to a 10W HID.

Jarvist holds the secchi disc and tape measure

Not surprisingly, the helmet mounted lights, although powerful, reduced visibility significantly, whilst the HID seemed to cope best. Still, there was a metre variation between Rich and I using the same Rude Nora on the same setting. More work needed we think. Overall, there was a 2m variation in visibility between all of the lights. This is too wide a range for UK sumps where visibility typically ranges from an anecdotal zero to 5m at best. The exception being Wookey Hole and Peak Cavern, where visibility can exceed the range of your light (but only just!!)


Can underwater in Porth yr Ogof

We then swam a little upstream and found a nice looking bit of passage to do some 'arty farty' video to turn into screen grabs. My photography underwater is just not up to scratch, so we figured video grabs were the best thing to try for at this stage.

Once done, we rode the flow out of the cave in pretty poor vis and crawled unceremoniously out of Tradesmans, trying desperately not to add to the pile of cave diving kit which has been dropped and swept away by the current, never to be seen again!

Data: Porth yr Ogof 25/03/2013, Richard Walker. Dived

Your name:	Rich Walker	Observation date:	25/3/2013
Site Visited	Porth yr Ogof

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Church Sinks Observations
The river water was Sinking into the river bed
Church sinks flora: NOT VISITED
Church sinks fauna: NOT VISITED
Church sinks water temperature: NOT VISITED
General Church Sinks observations: NOT VISITED

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Top Entrance Observations
Accessible by walking up the riverbed?: Yes
Top Entrance Flora: Moss,
Top Entrance fauna: A small bird - maybe a robin. Otherwise nothing.
Top Entrance water temperature: 3C
Top Entrance general observations: Entrance clear of thorns. Loose stones in entrance.
Dives done into Top Entrance?: Yes

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Top Entrance Dive Log
Top Underwater Visibility: Good
Top Water flow: Medium
Tope entrance underwater fauna:
Top Entrance other observations: Relined Cobbett's loop from iron shoe to upper cave water chamber. Line surveyed from iron shoe to airbell just short of UCWC.

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Tradesman's Entrance Observations
Tradesman's flora: NONE RECORDED
Tradesman's fauna: NONE RECORDED
Tradesman's water temperature: NONE RECORDED
Tradesman's water level: 30cm BELOW approx
Did you dive at Tradesman's Entrance?: Yes

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Tradesman's underwater visibility: See below
Tradesman's water flow: Medium
Tradesman's underwater fauna: Approximately 6 trout. Varying levels of pigmentation. One small bullhead.
Tradesman's general observations: Tin can, plastic bucket seen near entrance. Line in need of a little work to replace a few tie offs. Temp 4C (Uwatec gauge). Visibility readings - mutiple measurements made with Secchi disk, different light sources and two independent observers. Used: Little Monkey head light (LMHL), Halcyon Mini-Explorer LED light (HME), Halcyon 10W HID, Light and Motion Sola2000W video light. Observer 1: LMHL (low setting) - 3.6m HME - 4.6m Observer 2: LMHL (low) - 4.7m LMHL (m&high) - 4.2m HHID - 5.6m L&M (low setting) 3.8m

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Main Entrance Observations
Main Entrance flora:
Main Entrance fauna:
Main Entrance water temperature:
Main Entrance general observations:

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Resurgence Observations
Resurgence flora:
Resurgence fauna:
Resurgence water temperature:
General resurgence observations:

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Little Neath River Cave Observations
LNRC Observations:

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Final Observations
General Observations: We will return tomorrow to complete other observations

Blog Post - Wales weather

Wales weather

Heading over to Wales today, we were in no doubt that it is going to be a cold one...

Porth is usually only diveable in the height of summer (but we didn't have one last year) or the depths of winter. It is almost April, but it looks like we are still in the latter. Which is good, as it is freezing overnight and keeping the water levels down.

We took a quick look at Tradesmans entrance (Divers main entrance) and the water was clear although not at it's lowest..it is diveable.

Survey grids drawn up in wetnotes

I have treated myself to some new graphite pencils which are lovely to work with underwater. Rich has treated us to a new sonar underwater device which will speed up surveying immensley and we'll no longer need to use the painstaking method of builders tape measure. The line is well tagged and laid but for absolute maximum accuracy as well as passage dimensions, the route from Tradesmans entrance right through to Top entrance (a traverse) has been surveyed with tape measure by myself and Malcolm Stewart.

Blog Post, South Wales Road trip 2013

Tradesmans entrance 23rd March 17:00
by Steve Thomas

Well, it's looking fairly promising for this week...
Steve Thomas popped over to Porth Yr Ogof to take a quick look at the conditions and although they are borderline, the water is quite clear and levels are dropping.

It's a dirty job but someone has to do it.....
(and it's always me!!)

We have 3 days over in Wales planned. This involves the usual practice of staying at a caving club - which now apparently has wifi - but still no mobile signal.....and we have a pretty long list of jobs to do.
Last week I spent a not-very-stressful couple of hours turning my 12 litre cylinders back into sidemount bottles again by adding bands and snoopies. Then I loaded thick, plastic, sinking line which kinks for a pastime onto a large reel, in the hope of re-lining Cobbets Loop, which leads to a nice bit of dry cave called Upper Cave Water Chamber (UCWC). All being well, I'd really like to take some photos in here.

The line is tagged at 5m intervals. We have survey work to do and Rich has just purchased an echosounder device, which should speed up the process of surveying somewhat.
Over the years, Malcolm Stewart and I have been painstakingly surveying with silva compass, builders tape measure and ordinary depth guage to a high degree of accuracy.
We'll compare data before relying on our new device completely.

Fully loaded line reel. The line is thick, heavy and should last
a good few years.





Blog Post, North Wales Guests

Google Earth overlay for PB North Wales

Setting off today to Anglesey for Project Baseline North Wales.
It's an early start from Manchester. Last night Brett Thorpe and Rich Walker gave a talk about Project Baseline and briefed the divers about how to collect data and what the project was looking for.
Today we'll be diving the Kimya, a small ish wreck just out of Caernarfon.



Rich introduces the Secchi disc

The primary objectives today are to familiarise divers with the sites and they will be looking to set up a 'stake in the sand' photo point for observation divers to come back to and repeat their photographs, visibility readings, temperature readings and observations.

I printed off a couple of Secchi discs and laminated them so that we could experiment with them on todays dive. The plan is to measure visibility readings in ambient light, then try with 10 and 18W HIDs and compare readings. The Secchi disc is usually designed as a vertical visibility measuring tool, so it is down to experimentation to decide if it is of use to measure horizontal visibility.
Divers' anecdotal opionions on vixibility vary so much that some kind of standard is required.
We have printed one for Porth Yr Ogof, which will be a much greater challenge as measurememts will be dependent on the type of lighting the diver uses as obviously there is no ambient light in the cave.
If the Secchi disk proves to be a useful tool, we'll get a more heavy duty and durable version made up.





Cave Diving Group Visibility scale, which is generally used to describe prevailing conditions in the Yorkshire Dales, where visibility is directly governed by the effects of rainfall onto the peat moorland above the caves.

Guiness  -  Black with froth on top
Brown Ale
Pedigree - (Acceptable - very)
Lager
White Wine
Poteen