At the bottom of 'old' Notts Pot, are two sump pools, one active and one static. The active sump is choked by cobbles at a depth of -5m. The static sump is located at the end of a short passage to the left of the main active sump, below the final pitch of Notts Pot. Entry to the Notts Pot extension is through the static sump by a dive of approximately 210m.
The line is belayed to a bolt and passes through an arch to a transverse rift where a shuffle to the right leads to a descent of 9m. This point, Taffy Turnip's Turnaround, is the deepest part of the sump and a dye test showed that the mainstream enters here through impenetrable fissures. A tube leads off ahead to a sharp righthand bend beyond which the line is tied to an eyehole on the right. The route meanders around silt banks and can be low. A slot 80m from base is passed to the right of the line and this has required digging. Beyond this, the passage enlarges and turns left, followed shortly by a sharp right hand turn at a T-junction. The left hand passage closes down after 10m. A rise to -5m and descent to -8m over a couple of silt banks leads to a levelling off for a final 50m until a rising cobble slope is met. This is prone to slump down and block the passage, but is easily dug. A gradual rise from this point gains the surface of Notts Pot II.
The mainstream from here can be followed for 1300m to sump 2, initially flowing in a fine drained phreatic tube of low gradient for 700m. A nick point marks the start of a narrow canyon which conveys the stream for the remaining distance.
A series of passages, termed the Near Inlet Series (or 14-18 Series), can be entered at three places. A tube (Inlet 1) rising to the right immediately beyond the sump leads to a junction beneath a stalactite curtain. Slightly left leads to a small boulder floored chamber with a wet aven, climbed for 8m to a choke. Water entering through the boulders flows away under the left wall. To the right at the stalactite curtain, a hands and knees crawl in a tubular, mud-floored passage enters Inlet 0. To the right, a descent of a muddy ramp regains the sump whilst to the left, walking sized, ascending, muddy passage continues to Prosector Pot, passing a crawl on the left. A bold leap across the pot gains Moribund Inlet which chokes after only four metres. At the bottom of the pot is an impenetrable sump.
The crawl to the left is through glutinous mud and eventually joins a streamway (Passchendaele). Going right (upstream) the passage gradually lowers to a tight sump. Downstream, the water eventually sinks away into a boulder choke. However, a crawl can be entered on the left just before the stream disappears. This crawl continues to a junction with a stream. Right regains the main streamway, entering as Inlet 2; while going left enters a crawl, dug through boulders, into a small chamber. The water entering this area is believed to come from the chamber in Inlet 1.
In the mainstream, a canal starts 20m from the sump at a left hand bend and is 40m long. In two places, where the passage turns right, it is necessary to swim. At the downstream end of the canal, many boulders on the passage floor mark the presence of the wet and loose Daylight Aven, just off to the left. Opposite this, a calcite slope leads up to a calcite cascade and a further view up the aven.
Downstream leads past two tubes on the right (Inlets 3 and 4) which very quickly choke. The next inlet (Inlet 5) is situated on the left at a pool 180m from the start of Notts II. The water can be followed up, in a stooping height passage with formations, for 190m to where it emerges from a sump. A crawl to the right emerges in a chamber where a climb of 3m on the far side enters a well-decorated passage with many straws and helictites. A flat out section in a pool and a further well-decorated crawling passage lead to a chamber, 45m from the sump, with four ways radiating off. All close down except for the downslope continuation which is muddy and unpleasant and picks up a small stream. This lasts for 125m to a low section in liquid mud where the passage becomes too tight and requires further digging. A streamway can be heard beyond the mud blockage.
The main bore continues downstream from Inlet 5 and contains various sections which must be waded. Some formations are also seen in the roof. After 150m, Curry Inlet (Inlet 6) enters from the right. This is followed easily for 80m at which point the main tube is choked. The water emerges from a low crawl over boulders to the left which can be followed for 60m to an inlet sump. The first section contains many formations and at one point a calcite floor forces a crawl in the stream to the left.
From Curry Junction, the main tube begins to show some downcutting of the stream, which flows past a solitary stalactite: Vlad the Impaler. 115m later, a sharp right hand bend below a roof dome is the next landmark. Scaling this reached Inlet 6.5, which is little more than an alcove. A few metres further on is a larger roof dome and 90m beyond is Inlet 7 on the right.
Inlet 7 is a low muddy passage leading to a junction after 50m. To the right is a low cobble crawl eventually emerging after about 50m at a muddy aven and diminutive mud sump. To the left quickly opens out into the impressive Oliver Lloyd Aven, at least 30m high with two waterfalls, and as yet unscaled.
Just downstream from Inlet 7 is Inlet 8, merely a choked alcove above a cracked mud slope on the left. Below this point, the streamway becomes wider and block-strewn, with the largest passage cross-section found in the extension, measuring five by eight metres. After 50m, the stream cuts down into a narrow canyon in the centre of the passage: The Nick Point.
From the nick point a 1m wide canyon may be followed, passing beneath a bridge of jammed boulders (The Tay Bridge) and descending more steeply. Alternatively, the roof tube may be traversed, sometimes on ledges, sometimes by straddling the canyon. Thirty metres along the tube is a 4m column and 20m further on is Dome Inlet on the right. This is reached by a climb up, and 40m of passage leads to a final short, wet crawl which emerges at a 12m aven (unclimbed).
Downstream in the canyon, 110m from the nick point, at a prominent left hand bend, Sir Digby Spode's Inlet enters on the right. A short climb rigged with a handline leads to 30m of large muddy passage and an aven. The passage continues to the left and lowers to a short crawl ending at the impenetrable Bruno Kranski's Rising Sump, 100m from the mainstream junction. Scallop marks in the floor suggest that a considerable flow rises from this in flood. The aven (Count Lazlo Stroganoff's Aven) has been scaled for 25m past a ledge where a boulder is jammed. It can be seen to continue for at least a further 10m.
Back in the canyon, 50m further downstream, a climb by a right hand bend leads to Echo Inlet. A squeeze past a stalactite leads to a tight corner where the passage continues but is too tight to follow.
45m further downstream, a shower of water just beyond some jammed boulders marks the entry of Showerbath Inlet (Inlet 12). This can be entered by chimneying up before the boulders and stepping across the canyon. A crawl emerges in a high fault-aligned passage with water cascading from an aven. The passage ahead rises steeply over calcited boulders to a solid cobble choke, 60m from the main streamway.
Another 130m downstream from Showerbath Inlet, at a sharp righthand bend, a high narrow canyon (Inlet 13) enters from the left at stream level. This leads, after 50m, to a T-junction with a larger tube. To the left is mud-choked, but upstream to the right enters Mincemeat Aven after 30m. This is some 15m high with a view into a much higher aven to the east. Not far beyond, the passage ends at a series of narrow climbs to a squeeze. Another passage to the left beneath the aven leads for 60m to an inlet sump. This inlet lies directly below the dry valley on the surface, with Mincemeat Aven part way between Committee Pot (Pirate Pot in 'Northern Caves') and Kango Hole. Unfortunately, everything in this area is boulder-filled and very shattered, and a dry entrance seems fairly unlikely.
Below this point, the mainstream becomes wider and less sinuous. The roof tube is still present but it is impossible to traverse along it. Consequently, the next inlet (Inlet 14), indicated by an active flowstone cascade 90m downstream, is, as yet, unentered.
A further 65m on again, Inlet 15 is on the left above some calcited blocks bridging the passage. Entry is gained by climbing the flowstone cascade below the blocks. A stooping height passage leads for 170m over fragile rimstone pools fed by drips from the roof. The passage ends suddenly at the edge of a drop of 1.5m into a small chamber. An eyehole is followed by further small drops to a fissure in the roof which connects back to a side passage at the head of the drop into the chamber. Shortly beyond, 22m from the chamber, the passage sumps. A short freedive leads to a cross-rift airbell and a continuing sump at 2m depth.
The main streamway narrows again, with Green Tape Inlet (Inlet 16) on the right. The entrance to this is not obvious, but is reached via a slippery climb. 140m of low, wet crawling lead to a 'hanging death' boulder choke. Just before this on the left are three low passages joining together and leading to a small active streamway which is inaccessible.
Below this point, the streamway cuts down steeply via some small cascades until a final drop of 2m, where it is difficult to avoid the spout of water in wet conditions. At the foot of this cascade is a short, boulder-floored river chamber, Kleine Scheidegg. The stream flows away under the right hand wall, and a few metres beyond, entry into a low cobble-floored bedding is possible in low water conditions. After a few metres the stream is regained and the crawl continues for 30m to a left hand bend where the line for sump 2 is belayed in a roof dome where it is possible to sit up. The crawl continues for 10m, passing under two cross-rifts to the start of sump 2.
In very dry conditions sump 2 is 8m long, shallow, and contains an airbell in the middle. The sump is then freediveable, but it should be noted that the line is not belayed in the airbell. However, in normal conditions, the sump is probably nearer to 30m in length. On no account should it be freedived without first being checked by a fully equipped diver. This whole section below Kleine Scheidegg becomes impassable in high water conditions and fills to the roof in flood. Tide marks in the chamber show that the final sumps back up to a depth of up to 5m.
On surfacing from sump 2 the stream continues in a mud-coated phreatic passage for 20m to sump 3. Immediately on the left below sump 2 is an inlet with a significant stream. Inlet 17 may be followed upstream for 80m alternating between stooping and crawling over a muddy floor until a sump is met. A 2m diameter phreatic tube rises on the left 30m upstream from the main stream junction. A slippery ramp of 30° is climbed to a point requiring combined tactics. Above this the passage continues with a few formations to a balcony overlooking Kleine Scheidegg. The floor is 8m below.
Sump 3 is a dive of 295m in a large (2x3 metre) tube. There is a large airbell after 210m, though the line is not belayed here. An inlet of 1.5m diameter issues from the left wall of the airbell 1.5m above water level (Inlet 18) and is as yet unentered. 30m downstream of this is an underwater inlet on the right which appears low after 5m.
A cobble slope followed by a rise of 3m up a pot gains the surface of Notts IV. This consists of a block-strewn streamway with a moderate gradient which gives way after 30m to a silt-floored passage over which the the stream meanders for 70m until sump 4 is reached. This is undived, but has been followed for 10m, as far as diminishing airspace in a meandering roof tube allowed. Just before sump 4, a rising phreatic tube on the right ends after 15m at a loose boulder choke.