Blog Post: Porth Yr Ogof - Diving and Data. By Christine Grosart, Project Manager. 25th June 2016

     Porth Yr Ogof

An extremely busy year for both Rich and I meant that getting over to Porth this year was looking impossible, until I spotted a window of opportunity on a Saturday afternoon.

Of course, that means lining up the weather too and I kept a close eye on the Environment Agency River Levels Data website, which records the levels of the Mellte at regular intervals. Despite sporadic heavy showers, the water level in Tradesman's Entrance Station 3 was anecdotally low, the distance between the water surface and the top of the 'flat ledge' on the right being 64cm.

I decided to dive first and do the other data recordings at the other sites later. Kitting up in the car park, there were several mini buses of children going caving. I slid down to the water and to my horror, my go-pro 'pinged' from its string which had been tied to a bolt-snap and D-ring and vanished into the bubbling water.

Porth is notorious for eating dive gear, often dropped in the entrance and it is taken away by the fast flowing water, never to be seen again. I should have known better and put the go-pro in a pocket - but, furious with myself for not taking my own advice, continued with the dive in any case.

Standard photo of Tradesman's Entrance
Station 3

The flow in the entrance was moderate. I spotted 2 medium size trout which were pale in colour but not completely white, close to the first couple of tie-offs. I didn't have a helmet or helmet mounted lights, but used instead a Halcyon Focus hand held torch and back ups mounted on my harness. 

As I approached the Secci disc, I stopped so that I didn't disturb the visibility ahead.

The line is tagged with red cable ties at 50cm intervals so I put the focus onto a fairly tight beam and could just about make out the secci markings from exactly 5m away, counting the tags as I moved forward.

The depth of the Secci was 2.9m and the water temp was recorded as 13 degrees C.

I noted some detritus starting to form on the face of the secci, despite it facing downstream.

I continued upstream, noting some larger, whiter trout and 3 bullheads, one of which was grubbing around in the silt.

River Levels data. Standard image of Station 6.

There was a thick layer of silt on the normally clean washed passage floor and the viz seemed gloomy to me, with lots of particles in suspension.

I then approached the 'Pot' which has been neatly re-lined by Max Fisher, with a rope protector in situ, doing it's job to stop the line fraying over the edge of the pot.

This seems the way forward as I don't see much value in damaging the cave further by putting in a bolt for this purpose.

The flow seemed to get a little stronger as I continued upstream, possibly due to recent bursts of rain which may have started to make their way into the cave. As I got to the cobble slope which surfaces in Upper Cave Water Chamber, I was shoved quite violently down the tube and decided to turn around - which took some doing - as the flow was definitely getting stronger.

Children on their caving trips

I had the usual low viz roller coaster ride home and once de-kitted in the car park, headed back into the cave to look for my Go-Pro which I luckily found just behind the water entry spot, pinned to a rock by the high flow.

It was already past 4pm so I elected not to dive again but instead visit the other stations to take standard photos of each station and water temperature readings where I could.
It's a pleasant job to wander down to Main entrance (station 4) and sit in the tranquility once the cavers have gone home. I spotted a small brown fish darting around in the entrance pool - and one welly boot!
It's a short walk down to the resurgence where I took a temperature reading with my D-Timer and also up to Top entrance where there were some really pretty wild flowers growing. 
Back up the steps, a grey squirrel was busy running around the tree trunk. 

PB data sheets as an aide memoire

Depth gauge and reel, used for temperature data

Red Campion

Meadow Buttercup

Herb Robert

Data: Porth Yr Ogof. 25/06/2016. Christine Grosart. Dived.

Your name:	christine grosart	Observation date:	25/06/2016
Site Visited	Porth yr Ogof

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Church Sinks Observations
The river water was Flowing under the bridge
Church sinks flora: Not noted
Church sinks fauna: None seen
Church sinks water temperature: D-Timer would not record (too shallow)
General Church Sinks observations: Water partially flowing under the bridge, which was surprising given the initial low water levels in Porth. Wondering if the lunchtime rain had started to make it flow later on.

---

Top Entrance Observations
Accessible by walking up the riverbed?: Yes
Top Entrance Flora: Red Campion Meadow Buttercup Herb Robert
Top Entrance fauna: None
Top Entrance water temperature: Not read but 13 degrees during dive
Top Entrance general observations: 1 intact plastic carrier bag (removed) in river bed.
Dives done into Top Entrance?: No

---

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: Hartstongue fern
Tradesman's fauna: Grey Squirrel in tree by car park, top of steps
Tradesman's water temperature: 13
Tradesman's water level: 64cm (25 inches)
Did you dive at Tradesman's Entrance?: Yes

---

Tradesman's underwater visibility: 5.0 exactly with secci and tagged line, using Halcyon Focus on medium/tight beam. No helmet light.
Tradesman's water flow: Low in entrance, becoming higher beyond the pot and very high by Essers junction
Tradesman's underwater fauna: 2 medium size trout, pale but not completely white 2 large trout, mostly white 3 bullheads (white) throughout the cave and one seemed to be digging in the silt
Tradesman's general observations: Secci station depth: 2.9m Lots of particulate in the water, viz quite brown and poor. Lots of silt covering normally clean washed passages. Ladder had fallen down from first airbell so replaced it. New line in the pot looks very good and clean and rope protector doing a good job. Some snoopies have broken so a good job for a trainee to repair some. Silt screws on the sand banks before 4ways still totally solid. Lost go-pro in entrance so unable to shoot video or images (found post-dive but too late for a second dive.)

---

Main Entrance Observations
Main Entrance flora: Usual moss and ferns
Main Entrance fauna: 1 small brown fish darting around in the main entrance pool
Main Entrance water temperature: 12 (at 2.2m depth)
Main Entrance general observations: 1 lager can and 1 welly boot

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Resurgence Observations
Resurgence flora: None noted
Resurgence fauna: None noted
Resurgence water temperature: 13 (at 1m depth)
General resurgence observations:

---

Little Neath River Cave Observations
LNRC Observations:

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Final Observations
General Observations:

Data: Little Neath River Cave. 15/05/2016. Cristian Cristea. Dived

Your name:	Cristian Cristea	Observation date:	15th May 2016
Site Visited	Little Neath River Cave

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Church Sinks Observations
The river water was
Church sinks flora:
Church sinks fauna:
Church sinks water temperature:
General Church Sinks observations:

---

Top Entrance Observations
Accessible by walking up the riverbed?:
Top Entrance Flora:
Top Entrance fauna:
Top Entrance water temperature:
Top Entrance general observations:
Dives done into Top Entrance?:

---

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

---

Tradesman's Entrance Observations
Tradesman's flora:
Tradesman's fauna:
Tradesman's water temperature:
Tradesman's water level:
Did you dive at Tradesman's Entrance?:

---

Tradesman's underwater visibility:
Tradesman's water flow:
Tradesman's underwater fauna:
Tradesman's general observations:

---

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

---

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

---

Little Neath River Cave Observations
LNRC Observations: First trip down through Bridge Cave sump 1 to LNRC and some distance crawling in low water in The Canal before deciding to turn around. Sump 1 was pretty clear, at least 3-4m visibility, with a thick layer of brown foam on surface near entrance. There was also a strange smell, felt on the way back from the sump. Also spotted four big trouts in the sump1 and 2 other smaller ones in The Canal. No litter found in the cave, and the rescue drums were intact and sealed. Some footage taken on a gopro, will check it later.

---

Final Observations
General Observations:

Data: Porth Yr Ogof. 14/05/2016. Rupert Massey. Dived

Your name:	Rupert Massey	Observation date:	14/05/16
Site Visited	Porth yr Ogof

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Church Sinks Observations
The river water was
Church sinks flora:
Church sinks fauna:
Church sinks water temperature:
General Church Sinks observations:

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Top Entrance Observations
Accessible by walking up the riverbed?: Yes
Top Entrance Flora:
Top Entrance fauna:
Top Entrance water temperature:
Top Entrance general observations: Nothing of note, the water level was low and the visibility was good.
Dives done into Top Entrance?: No

---

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

---

Tradesman's Entrance Observations
Tradesman's flora:
Tradesman's fauna:
Tradesman's water temperature: 12 degrees C
Tradesman's water level: approx 50cm BELOW step
Did you dive at Tradesman's Entrance?: Yes

---

Tradesman's underwater visibility: Medium
Tradesman's water flow: Medium
Tradesman's underwater fauna: 2 albino trout. Definitely fewer than I have seen before, possibly as a result of flow.
Tradesman's general observations:

---

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

---

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

---

Little Neath River Cave Observations
LNRC Observations:

---

Final Observations
General Observations:

Blog Post: by Maxwell Fisher. 19th & 26th April 2016

Tuesday the 19th saw me diving at Porth Yr Ogof for the first time in 2016.
I had been monitoring the weather forecasts and River Mellte gauge levels for some time, hoping to get in. Finally time off work and weather aligned and I was able to make a trip over.
The water level was approximately one fin length (Mares Quattro) below the step; steady progress was made along the passage in light to moderate flow. 

Line abrasion from flow in the 'Pot'

The first point of note was the abrasion partway down the first pot. The sheath of the line was worn through, exposing the core which showed some signs of wear. I decided it wasn’t about to break on me anytime soon and continued surfacing in the first airbell. 
A quick check on gas pressures was made before I continued onto the next airbell. Again a quick check on gas pressures was made before continuing onto the upper cave water chamber. 
About 10m before the junction to Esser’s passage, some loose line was billowing down the passage. I continued on and saw that it was coming from the pot leading down to the rest of the cave. I continued along the main line and surfaced in the upper cave water chamber, the boulder slope easily passed in a wetsuit and 7l cylinders. 

I crawled through to the chamber proper and removed my fins and one 7l cylinder, keeping one on to pass the next short sump. This sump is quite short, at 4m long I would estimate and had crystal clear waters. A cobble slope restricts entry to one point. Surfacing in a section of cave I had not visited before, I dumped my kit and began crawling to find the next sump. This part of the cave is a wide bedding with a cobble floor. 
The next sump soon presented itself and I spent a few moments floating in it trying to glimpse what was beyond. Retracing my route back through the cobbles, I was soon kitting up ready to pass the short sump back. 
I had ample gas reserves left so decided to tidy up the line billowing out of Esser’s passage on my exit. I pulled it in hand over hand, coiled and attached it to the bolt above the pot to keep it out of harms way. It was clear that the belay at the bottom of the pot was intact, however I decided to leave that task for another day, riding the gentle flow of the cave back to the tradesman entrance.

After a quick sandwich I decided to have a walk up the dry river to locate the other entrances which I had not looked at before, some pictures are shown below:

Cwmbran Entrance

Cwmbran Entrance

Top Entrance

Main Entrance

I decided to visit again on the 26th to make repairs to the line, I planned two dives: the first to repair the pot line, the second to repair the Esser’s line. I had been unable to get a good fill in my 7’s, so decided to dive with a part full 7 and a part full 12 to give me plenty of time to fix the line in the pot. The flow was slightly lower today, the gauge level having dropped from 0.26m to 0.23m since my visit the previous week. 

Easy progress was made to the pot where I spent a good 10 minutes assessing before I made any changes. I examined the roof, finding a small air bell but no natural anchors to create a deviation from. I noted a flake near the bottom of the pot which I thought to be useful for holding the line away from the pot wall. I tentatively cut the old line and began attaching the new one working upstream so as to always have contact with the exit line. In total this dive lasted 32 minutes, I was very chilled on exit. 

A diagram of the current situation in the pot is shown below (side view):

The carpark afforded no warmth during lunchtime with sleet and snow showers. A chilly diver re-entered the water with the intention of fixing the Esser’s passage section. 

Easy progress was made using just about 1/3 of one cylinder leaving 1/3 of the second cylinder to work with, I removed my coil from the S/s bolt I had made the previous week and descended the pot, new territory for me. 

To my surprise three belays at the bottom of the pot were intact, the break in the line having occurred much further into the cave. Once at the bottom of the pot the rock belay is intact, moving along the passage a little further a lead weight belay was intact and further again the final intact belay was a thread in the right hand wall opposite a cobbly slot in the floor which I believe is Esser’s passage itself (?)

I had a large amount of rope in my hand at this point, having added to the coil to this point rather than reducing it and was fairly cold so I decided to exit and come back again to further explore this section of the cave. I was glad to get back to the surface, ditch my wetsuit and drive home with the heating on full blast.

A plan view sketch has been drawn of the situation:

Data: Porth yr Ogof. 26/04/2016. Maxwell Fisher. Dived.

Your name:	Max	Observation date:	26/04/2016
Site Visited	Porth yr Ogof

---

Church Sinks Observations
The river water was Flowing under the bridge
Church sinks flora:
Church sinks fauna:
Church sinks water temperature:
General Church Sinks observations: Small flow down river

---

Top Entrance Observations
Accessible by walking up the riverbed?: Yes
Top Entrance Flora:
Top Entrance fauna:
Top Entrance water temperature:
Top Entrance general observations:
Dives done into Top Entrance?: No

---

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

---

Tradesman's Entrance Observations
Tradesman's flora: The usual
Tradesman's fauna:
Tradesman's water temperature: 8 c
Tradesman's water level: fin lengthbelow
Did you dive at Tradesman's Entrance?: Yes

---

Tradesman's underwater visibility: 5m
Tradesman's water flow: low for Porth
Tradesman's underwater fauna: Some fish seen, white ones with spots. Two mating frogs/ toads seen near exit on way out
Tradesman's general observations: Line repaired in first pot and bottom belay moved from rock at base of pot to flake which holds line away from the wall, tube used to protect line running over lip of pot. Not noticed before but is actually a small air bell above the pot. A plastic tub (sofonlime??) could be brought in flooded then filled/ sealed and used as a float belay above pot if further problems occur as an option instead of drilling a bolt. Second dive attempted to sort out Esser's line, descended pot and continued along passage, line was intact past lead weight belay to thread belay on right hand wall, then had been quite cold and I had a large amount of rope to deal with so tidied it and exited shivering all the way out.

---

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

---

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

---

Little Neath River Cave Observations
LNRC Observations:

---

Final Observations
General Observations: Hail stones/ snow in April !

Data: Porth Yr Ogof. 19/04/2016. Maxwell Fisher. Dived.

Your name:	Max Fisher	Observation date:	19/04/2016
Site Visited	Porth yr Ogof

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Church Sinks Observations
The river water was Flowing under the bridge
Church sinks flora:
Church sinks fauna:
Church sinks water temperature:
General Church Sinks observations: Very small flow under bridge

---

Top Entrance Observations
Accessible by walking up the riverbed?: Yes
Top Entrance Flora:
Top Entrance fauna:
Top Entrance water temperature:
Top Entrance general observations: Top entrance clear, water well down inside below line, easy access to water
Dives done into Top Entrance?: No

---

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

---

Tradesman's Entrance Observations
Tradesman's flora:
Tradesman's fauna:
Tradesman's water temperature: 8
Tradesman's water level: One fin length below step
Did you dive at Tradesman's Entrance?: Yes

---

Tradesman's underwater visibility: 5
Tradesman's water flow: lowish
Tradesman's underwater fauna: some fish seen throughout cave
Tradesman's general observations: See: http://www.cavedivinggroup.org.uk/cgi-bin/CDG/BBS/threadall.html?Thread=4570

---

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

---

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

---

Little Neath River Cave Observations
LNRC Observations:

---

Final Observations
General Observations:

Data: Porth Yr Ogof. 08/04/2016. Rupert Massey. Dived.

Your name:	Rupert Massey	Observation date:	08/04/16
Site Visited	Porth yr Ogof

---

Church Sinks Observations
The river water was
Church sinks flora:
Church sinks fauna:
Church sinks water temperature:
General Church Sinks observations:

---

Top Entrance Observations
Accessible by walking up the riverbed?:
Top Entrance Flora:
Top Entrance fauna:
Top Entrance water temperature:
Top Entrance general observations:
Dives done into Top Entrance?: No

---

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

---

Tradesman's Entrance Observations
Tradesman's flora:
Tradesman's fauna:
Tradesman's water temperature:
Tradesman's water level: Around 25cm BELOW step.
Did you dive at Tradesman's Entrance?: Yes

---

Tradesman's underwater visibility: approx. 5m
Tradesman's water flow: Medium. Certainly the most when I have dived it.
Tradesman's underwater fauna: 5 albino trout of varying size. One in particular was large and strikingly spotted.
Tradesman's general observations: Lines in good condition. It may be a good idea to consider further reinforcing the line at the point it descends the first shaft.

---

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

---

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

---

Little Neath River Cave Observations
LNRC Observations:

---

Final Observations
General Observations:

Data: Porth Yr Ogof. 11/10/2015. Mark Vaughan. Dived.

Your name:	Mark Vaughan	Observation date:	11/10/15
Site Visited	Porth yr Ogof

---

Church Sinks Observations
The river water was Flowing under the bridge
Church sinks flora: sorry not observed.
Church sinks fauna:
Church sinks water temperature:
General Church Sinks observations:

---

Top Entrance Observations
Accessible by walking up the riverbed?:
Top Entrance Flora:
Top Entrance fauna:
Top Entrance water temperature:
Top Entrance general observations:
Dives done into Top Entrance?: No

---

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

---

Tradesman's Entrance Observations
Tradesman's flora: None
Tradesman's fauna: 3 no trout
Tradesman's water temperature:
Tradesman's water level: below
Did you dive at Tradesman's Entrance?: Yes

---

Tradesman's underwater visibility: 3 mtrs
Tradesman's water flow: unknown
Tradesman's underwater fauna: 2 trout with usual bright colour's and 1 with white color's no pigment
Tradesman's general observations: None observed

---

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

---

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

---

Little Neath River Cave Observations
LNRC Observations:

---

Final Observations
General Observations: the general color of the water was very brown which i found was not in keeping with the small flow.

Data: Porth Yr Ogof. 11/10/2015. Mark Vaughan. Dived.

Your name:	Mark Vaughan	Observation date:	11/10/15
Site Visited	Porth yr Ogof

---

Church Sinks Observations
The river water was Flowing under the bridge
Church sinks flora: sorry not observed.
Church sinks fauna:
Church sinks water temperature:
General Church Sinks observations:

---

Top Entrance Observations
Accessible by walking up the riverbed?:
Top Entrance Flora:
Top Entrance fauna:
Top Entrance water temperature:
Top Entrance general observations:
Dives done into Top Entrance?: No

---

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

---

Tradesman's Entrance Observations
Tradesman's flora: None
Tradesman's fauna: 3 no trout
Tradesman's water temperature:
Tradesman's water level: below
Did you dive at Tradesman's Entrance?: Yes

---

Tradesman's underwater visibility: 3 mtrs
Tradesman's water flow: unknown
Tradesman's underwater fauna: 2 trout with usual bright colour's and 1 with white color's no pigment
Tradesman's general observations: None observed

---

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

---

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

---

Little Neath River Cave Observations
LNRC Observations:

---

Final Observations
General Observations: the general color of the water was very brown which i found was not in keeping with the small flow.

Data: Porth Yr Ogof. 01/09/2015. Maxwell Fisher. Dived.

Your name:	max	Observation date:	01/09/2015
Site Visited	Porth yr Ogof

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Church Sinks Observations
The river water was
Church sinks flora:
Church sinks fauna:
Church sinks water temperature:
General Church Sinks observations:

---

Top Entrance Observations
Accessible by walking up the riverbed?:
Top Entrance Flora:
Top Entrance fauna:
Top Entrance water temperature:
Top Entrance general observations:
Dives done into Top Entrance?: No

---

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

---

Tradesman's Entrance Observations
Tradesman's flora:
Tradesman's fauna:
Tradesman's water temperature: 12
Tradesman's water level: below
Did you dive at Tradesman's Entrance?: Yes

---

Tradesman's underwater visibility: 5m+
Tradesman's water flow: low
Tradesman's underwater fauna: small trout in entrance, larger one found between rawbolt & 4 ways airbell
Tradesman's general observations:

---

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

---

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

---

Little Neath River Cave Observations
LNRC Observations:

---

Final Observations
General Observations:

Data: Porth yr Ogof. 18/08/2015. Maxwell Fisher. Dived.

Your name:	max fisher	Observation date:	18/08/2015
Site Visited	Porth yr Ogof

---

Church Sinks Observations
The river water was Flowing under the bridge
Church sinks flora: small flow down river
Church sinks fauna: n/a
Church sinks water temperature:
General Church Sinks observations:

---

Top Entrance Observations
Accessible by walking up the riverbed?: Yes
Top Entrance Flora:
Top Entrance fauna: 2 trout just inside entrance area
Top Entrance water temperature: warm, 5mm wetsuit dive
Top Entrance general observations:
Dives done into Top Entrance?: Yes

---

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

---

Tradesman's Entrance Observations
Tradesman's flora: green ones
Tradesman's fauna: 2 trout
Tradesman's water temperature: warm, 5mm wetsuit
Tradesman's water level: below
Did you dive at Tradesman's Entrance?: Yes

---

Tradesman's underwater visibility: 4
Tradesman's water flow: medium
Tradesman's underwater fauna: 2 trout
Tradesman's general observations: line ok all way to four ways airbell

---

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

---

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

---

Little Neath River Cave Observations
LNRC Observations:

---

Final Observations
General Observations:

Blog post: Flood pulses and Secchi measurements....

There has been lots of work going on at Porth yr Ogof thanks to divers beginning to get on board with Project Baseline South Wales Caves.
Somerset Section Cave Diving Group divers Mike Thomas and Kevin Hilton have been visiting Porth over the summer and not only has the Secchi disc been installed, but the line leading up to the disc has now been tagged. This means that visibility measurements can be taken on the way in, without the need for a tape measure.

Please not the following message from Mike for details on the line and current conditions in Porth yr Ogof:

"On the 8/10/2015 on a trip to sump 8 and 9 in Porth yr Ogof we took the opportunity to fit distance marker tags on the line approaching the visibility disc. You now do not need a tape measure to work out the distance from the disc. 
From 5m back every 1m is marked with a line arrow, every 50cm is marked with a white cable tie and every 25cm with a red cable tie. So by counting the tags from the point you can see the disc until reaching the disc you now know what the distance is. Other work done was relining of sump 8 and 9. 
I would suggest the reservoir upstream of the cave has released a large volume of water recently as the line upstream of four ways junction was completely buried in sand and had to be dug out for around 10m distance. Also several line Belays found to be broken and a repair was made. I hope it was the same flood pulse that damaged the belays. As a point of note it's good practise to carry some belays on dives to repair stuff ..." M.Thomas

Sump 8-9 Porth yr Ogof Upper cave.
Photo M.Thomas

If you are visiting Porth for a dive, please make sure that the reservoir are not planning to release water while you are in there! 
Mike reported that he saw NO trout at all - of any ethnicity - and it is presumed that they have simply been flushed out by the flood pulse (but not entirely sure how we could prove this).

As a result of flood pulses, some of the belays have been destroyed. If you are diving here please make any repairs if you are able to, as it all helps facilitate a clean exit in low visibility conditions (that diver may be you!)

We are experimenting with a aide memoire sheet which Rupert Massey used to good effect recently. He came back with a very comprehensive set of data for the project. To download your copy, click here:

Project Baseline South Wales Caves (PYO) aide memoire

Mandatory post-porth icecreams.
Photo M.Thomas

It is advised to contact Welsh Water 0800 0520145 to find out the dates and times of when they plan to release water from the reservoir as it seems that the flow in Porth increases significantly, with sand some 10cm deep being found in a normally clean washed side passage (on approach to Esser's passage). 

"Dwr Cymru Welsh Water is carrying out essential investment works at Ystradfellte reservoir and dam. Between June and October, we may occasionally need to release some additional water from the dam, which could see an increase in river levels. We do not expect the levels to increase significantly but would ask that people undertaking any recreational activities in the local river and caves bear this in mind when planning their activities. Dwr Cymru Welsh Water does not accept any liability in respect of any of these activities. These activities are 
carried out entirely at the individual's own risk."

Data: Porth Yr Ogof. 25/07/2015. Rupert Massey. Dived.

Your name:	Rupert Massey	Observation date:	25/07/15
Site Visited	Porth yr Ogof

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Church Sinks Observations
The river water was
Church sinks flora:
Church sinks fauna:
Church sinks water temperature:
General Church Sinks observations:

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Top Entrance Observations
Accessible by walking up the riverbed?: Yes
Top Entrance Flora:
Top Entrance fauna:
Top Entrance water temperature: 12 (Suunto Zoop)
Top Entrance general observations: A couple of items of litter (fragments of bin bag) removed from river bed. Top entrance clear of debris.
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:
Tradesman's fauna:
Tradesman's water temperature: 13 (Suunto Helo2)
Tradesman's water level: 57cm BELOW
Did you dive at Tradesman's Entrance?: Yes

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Tradesman's underwater visibility: 2.1m
Tradesman's water flow: (Purely) visual estimation: 1.5m/s
Tradesman's underwater fauna: 3 x trout within 20m of entrance. Between 8-12'' long.
Tradesman's general observations:

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Main Entrance Observations
Main Entrance flora:
Main Entrance fauna:
Main Entrance water temperature: 11 (Suunto Zoop)
Main Entrance general observations: Again several pieces of plastic rubbish bag recovered. Foam observed in several pools inside Main Entrance.

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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: Dived from Tradesmans, made measurements then headed for the Top entrance/Upper cave junction as last time. Conditions were sub-optimal so decided to retreat and wait to visit the Upper Cave.

Data: Porth Yr Ogof. 04/07/2015. Rupert Massey. Dived.

Your name:	Rupert Massey	Observation date:	04/07/15
Site Visited	Porth yr Ogof

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Church Sinks Observations
The river water was
Church sinks flora:
Church sinks fauna:
Church sinks water temperature:
General Church Sinks observations:

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Top Entrance Observations
Accessible by walking up the riverbed?:
Top Entrance Flora:
Top Entrance fauna:
Top Entrance water temperature:
Top Entrance general observations:
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:
Tradesman's fauna:
Tradesman's water temperature:
Tradesman's water level: Approx. 60cm
Did you dive at Tradesman's Entrance?: Yes

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Tradesman's underwater visibility: Medium
Tradesman's water flow: Low
Tradesman's underwater fauna: 3 brown trout - not entirely albino, pale spots 4-5 bullheads 2 crustaceans possibly Niphargus or Gammarus (past Four Ways towards Top Entrance/Essler's passage junction.
Tradesman's general observations:

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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:

---

Little Neath River Cave Observations
LNRC Observations:

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Final Observations
General Observations: Next time I will take a tape measure and camera and write record something of more quality!

Data: Little Neath River Cave. 24/05/2015. Christine Grosart. NOT dived.

Your name:	Christine Grosart	Observation date:	24/05/2015
Site Visited	Little Neath River Cave

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Church Sinks Observations
The river water was
Church sinks flora:
Church sinks fauna:
Church sinks water temperature:
General Church Sinks observations:

---

Top Entrance Observations
Accessible by walking up the riverbed?:
Top Entrance Flora:
Top Entrance fauna:
Top Entrance water temperature:
Top Entrance general observations:
Dives done into Top Entrance?:

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

---

Tradesman's Entrance Observations
Tradesman's flora:
Tradesman's fauna:
Tradesman's water temperature:
Tradesman's water level:
Did you dive at Tradesman's Entrance?:

---

Tradesman's underwater visibility:
Tradesman's water flow:
Tradesman's underwater fauna:
Tradesman's general observations:

---

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

---

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

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Little Neath River Cave Observations
LNRC Observations: NO diesel smell anywhere in the cave. One small bullhead in Sump 1 LNRC. Water looked clear with brown tinge. No foam. Water levels average. White substance on the mud bank (rescue dump) subsided since last visit and only minor trace remains.

---

Final Observations
General Observations:

Data: Little Neath River Cave. 27/05/2015. Max Fisher. Dived.

Your name:	max	Observation date:	27/05/2015
Site Visited	Little Neath River Cave

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Church Sinks Observations
The river water was
Church sinks flora:
Church sinks fauna:
Church sinks water temperature:
General Church Sinks observations:

---

Top Entrance Observations
Accessible by walking up the riverbed?:
Top Entrance Flora:
Top Entrance fauna:
Top Entrance water temperature:
Top Entrance general observations:
Dives done into Top Entrance?:

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

---

Tradesman's Entrance Observations
Tradesman's flora:
Tradesman's fauna:
Tradesman's water temperature:
Tradesman's water level:
Did you dive at Tradesman's Entrance?:

---

Tradesman's underwater visibility:
Tradesman's water flow:
Tradesman's underwater fauna:
Tradesman's general observations:

---

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

---

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

---

Little Neath River Cave Observations
LNRC Observations: Through bridge cave sump to sump 2 via canal, and a quick look about halfway back up to flood entrance. A few cut offs from zip ties found in sump (retrieved), 4 big fish (trout) is bridge cave sump. water quality fine throughout cave, no sign or smell of diesel.

---

Final Observations
General Observations:

Data: Porth Yr Ogof. 24/05/2015. Michael Thomas. Dived. (Christine Grosart - surface photos)

Your name:	Michael Thomas	Observation date:	24/05/2015
Site Visited	Porth yr Ogof

---

Church Sinks Observations
The river water was
Church sinks flora:
Church sinks fauna:
Church sinks water temperature:
General Church Sinks observations: Not visited

---

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

---

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

---

Tradesman's Entrance Observations
Tradesman's flora:
Tradesman's fauna:
Tradesman's water temperature: 9 C
Tradesman's water level: 30 cm below ledge
Did you dive at Tradesman's Entrance?: Yes

---

Tradesman's underwater visibility: Secci: 4m hand held light monkey, 3m helmet mounted rude nora
Tradesman's water flow: medium - high
Tradesman's underwater fauna: 1 trout - all white
Tradesman's general observations: Secci Disc installed just upstream from Cwmbran junction

---

Main Entrance Observations
Main Entrance flora: Harts tongue ferns (CSG)
Main Entrance fauna:
Main Entrance water temperature: Not taken
Main Entrance general observations: Major new collapse on left hand cliff on the approach to main entrance. Large boulders on the path and another large boulder hanging above.

---

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

---

Little Neath River Cave Observations
LNRC Observations:

---

Final Observations
General Observations:

Blog Post: Secchi Disc is go!

Secchi disc in Porth Yr Ogof
Photo: Mike Thomas

The secchi disc is in!

Following several false starts due to weather and quite a bit of discussion about how to do it, we've finally attached to secchi to a pot of concrete and found somebody else to drag it into the cave for us!

In seriousness, we're grateful to Mike Thomas, a CDG diver, for agreeing to take the disc in today and try some visibility measurements. He was headed over to Porth Yr Ogof for a dive in any case and I was heading to the next valley to take a group caving at Little Neath River Cave - where we also took a photo of sump 1 (station 7).

Mike pulling the Secchi disc into a fast flowing
Tradesmans Entrance, PYO

I ran over to Porth first to drop off the secchi and took some photos of Main Entrance (Station 4), Tradesman's Entrance (Station 3) and the River levels (Station 6).

I had been wondering, now that the secchi was about to be in place, whether there was any value in keeping the above ground stations. They all form part of the Porth story but seemed unlikely to change very much. Besides, this is a diving project after all.

Porth Main Entrance - in front of the new rock fall!

I considered dropping the surface observations and stations and only keeping the underwater ones - until I visited Main Entrance today!
I was very surprised to see what looked like a very recent collapse. A huge boulder blocked the path to the cave entrance and several other large, tv sized rocks had come down.
So much for nothing changing!
I'm inclined to keep the surface observations as part of the project for now - it just got interesting!

New rock fall by Main Entrance, PYO

Please take care when visiting Main Entrance - there is another massive   boulder just 'hanging' there above the path...

Mike took two viz measurements, one with a hand held light monkey (4m) and one with a helmet mounted Rude Nora 2 caving/diving torch (3m). He had already been upstream and was keen to point out that these were not 'true' visibility readings.

Significant rock falls close to PYO Main Entrance

He also noted one very white trout and shot some video - and also 2 bullheads.
This (in comparison to other reports) is quite a small amount of life, so it will be interesting to see if the abundance improves by the time another diver reports in.

Meanwhile, over in the next valley, I visited Sump 1 of LNRC (Station 7) and my eagle eyed cavers spotted a bullhead in the shallows. No trout this time though (that we could see). No foam and pleasingly, no diesel/paraffin smell. The white substance on the mud bank near the sump (@rescue dump) has almost gone.

Blog Post: Talk in Bristol on Project Baseline

On 14th May, Christine was very proud to represent Project Baseline at Portway Football club for various Bristol based BSAC clubs. The event was organised by Bob Rodgers and was well attended.

Christine talked about the inception of Project Baseline, what the project aims to do and how it is implemented at grass roots level. She talked about her own project at Porth yr Ogof in South Wales as well as the Portland Harbour Wrecks project.

If you would like Christine or Richard to give a talk on Project Baseline, please contact them via this Blog site.