Thanks for the replies Ben & Alastair..... I got there, too, after a bit more reading and research! The device was in Silent Mode, and pressing the MEM (data symbol) and FUNC keys together for 2 seconds restored the normal data saving mode. (y) The floppy disk symbol in silent mode interests...

Have an issue arisen with a Disto-XBLE edition (Chinese board?). When in session mode (having cleared any previous data) the 'shot counter' in the top right corner of the disto's window no longer displays the number of shots taken. This would usually show a number divisble by seven, if your...

Clever little detector/logger, Stuart! As mentioned earlier in the thread I've used OB method for many tests - had a few misfires now and again, but 90% happy with the method and have successfully repeated a test over a 3km drainage route, and most recently a 4km one. (a fluorometer would be...

Thanks, Stuart, I get you on all that. We have a reasonably fast moving stream I'd say in the order of 20-30cm/sec - at least as far as the eye can see (and in wet weather it can be heard rushing or falling further ahead), so I'd say a fairly quick flow-through time is to be expected. To be...

I wonder what quantities you were injecting to turn both small (Barbon Beck) and medium (Dee) size rivers green! Last night I introduced a 100ml concentration of fluorescein (about 4-5g of powder) at the downstream limit of a cave to test a putative distance of under 100m to another nearby...

The 'detectors' will be people looking for it! ;) Yeah, I know I could put swabs in (have always done that with OBA), but then it's another trip to collect them etc. etc. In this scenario, we just want a quick visual on the evening: either they see it or they don't.

Thanks for confirmation (y) If I make up a solution, should it be released into the stream slowly?....so as to 'string out' the plume? Or do you just tip it in and let the stream do the work? I'm only thinking that perhaps a short plume has a greater chance of being missed by observers. The...

Thanks everyone for all your suggestions....and hilarious stories/anecdotes! - it sure is a substance to be reckoned with! Stuart France - thanks for the detailed response. I'm quite familiar with using OBA and have done many tests using the cotton wool and UV light method - many of these...

Many thanks for the link, Ian (y)

Can anyone recommend a good supplier/source of liquid fluorescein dye (or perhaps pwder if that is the preferred format these days? There's a lot of stuff online, but much of it looks like 'drain tester' stuff which I doubt is the real mccoy.

I think he might mean Penguin Hall...which is the short pitch after the free-hanging 3rd pitch, at a convergence of several avens. And thanks for the fine accolade you've awarded it! We enjoyed exploring it. It's certainly a novel hole with interesting situations. A shame it never hit that...

Great write-up, Tim, it all comes flooding back! ;) Looking forward to the next episode! p.s. I tend to agree that digging the lower cave might be worth a go, it was quite tempting at the time!

Red Rose at Bull Pot Farm have a couple of camping gardens, been very popular during the Covid years...but not in the current weather!  ;D www.rrcpc.org.uk

Up here in the Dales walls have been standing for hundreds of years  ;)

- AYGILL CAVERNS  -  NOW OPEN FOR BUSINESS - On the 8th August a team of five Red Rose members completed work on the choke beneath the 1st pitch (Traverse Pitch). Further walling of the hole in the floor stabilsed loose material and now allows a simple descent of 2m into a solid rift and the...