Marilyn Pot to Henslers Master Cave

Our original permit was for Rat Hole, however following concerns about the impending rain on the run up to the weekend we were able to change the permit to another equally interesting though less floodable alternative: Marilyn, the new entrance to the Gaping Gill system.

After meeting up with some folk from YUCPC who were doing Flood Entrance and Dihedral on the same day, we had breakfast and headed over to Clapham. After some faff with the tacklesacks we headed up the hill to arrive at Marilyn at around 1:15pm. The entrance was easy to find: Simply take a bearing to the right approximately half way between the wall and the footpath after crossing the double-style near Bar Pot, and walk for approximately 50m. The entrance is a huge and rather well constructed concrete-surrounded metal tube in an obvious shakehole.

Gary headed down to rig the first pitch and Laura and I soon followed. The first shaft reaches a rebelay. Below here a short scramble/descent reaches a further rebelay, above a slightly constricted rift which descends several metres to a ledge with lots of back-filled spoil. A further rebelay leads onto another short scramble/descent to the bottom of the pitch. A 40m rope, one sling and four bolts were ample for the entirity of this section.

A short blasted crawl leads soon to the top of Niagra pitch. There is a lot of loose rock at the pitch head, as well as on the ledge part way down, and so despite the pitch being rebelayed, it would be advisable for each person to completely clear the shaft before the next descends or ascends. A bolt about three metres back from the pitchhead provided backup, and a Y-hang was then possible off the right hand wall (one bolt in situ and one required placement). This descends to an easy deviation (in-situ hanger), and the spectacular proportions of the shaft become apparant. The rebelay is then reached (one more bolt required), on a muddy sloping ledge with lots of loose rocks. One further deviation (in situ hanger and cord) and then the floor is reached, only 30m upstream from the third pitch of Disappointment Pot. We had a 30m rope for this entire pitch, however we had to rig very tightly, and so ideally a 35+m would be more ideal in future.

The route down Disappointment was then followed with maximum efficiency, as the water levels were nice and low. Our only problem came in finding a backup point for the penultimate pitch, and we had to trust a non-too steady looking block, on the assumption that we weren\'t going to require it\'s assistance! The chamber between here and the final pitch was quite impressive. We soon reached Henslers Master Cave: We had intended to do the connection to Bar Pot, however, with a meet-back time of 8pm in Clapham arranged with the others we decided conveniently against the 15 minute muddy crawl. Instead we had a stomp down the amazing and huge downstream passage, took a few photos and commenced an enjoyable and efficient ascent.

Overall a very pleasurable trip, quite easy going with no real awkwardness or difficult bits, but lots of fun short pitches and impressive chambers, and the excellent Henslers Master Cave streamway to reward us at the bottom. Would be nice to return for a longer trip to explore the connection to Mud Hall: A trip from Marilyn to main chamber via Henslers old crawl and Mud Hall would be an excellent trip, although would probably require getting underground before 11am.