1961: First dive in Cocklebiddy by divers from Western Australia Speleological Group (WASG). Managed to establish that there was a submerged tunnel, 200 metres from the cave entrance, but were unable to swim much distance due to lack of gear.

1972: First large scale expedition. Adelaide divers were Ian Lewis, Phil Prust, Dave Warnes and Bob Turnbull while Bob Lea, and Ron and Denyse Doughton were from Sydney. Several hundred metres of line were laid in a northward direction.

1974: Keith Dekkers and Hugh Morrison from Perth headed a team and pushed Cocklebiddy to 500 metres of under water passage.

1975: The Keith Deckers and Hugh Morrison team again tackled the cave but did not extend the cave due to compressor problems.

1976: A joint West and South Australian team was organised with many of the previous divers and the addition of Ron Allum and Peter Stace. R Beilby and Hugh Morrison push the cave to 1,000 metres and discovered the first air chamber now known as the "Rock Pile", a long lake with a 20 metre high and 80 metre long pile of large loose rocks. Over the Rock Pile, the continuing submerged passage was pushed to 150 metres.

Cocklebiddy Lake | Photo: Greg Bulling

1977: In July, a South Australian team push an additional 350 meters into the second sump making a total penetration of 500 metres past the Rock Pile.

1977: In August, a Western Australian team including Morrison, Simon Jones and Dekkers added another 500 meters. This was the first trip where an under water "sled" was used. The sled transported 15 dive cylinders in the first sump to the Rock Pile and assisted in extending the second sump to over a kilometre in a mammoth 11 hour dive. Cocklebiddy was starting to give up its secrets.

1979: In May, a Western Australian team of 9 divers led by Morrison, Jones and Dekkers returned with two sleds and 40 dive cylinders. The method at that time was to swim the sleds laden with cylinders to the Rock Pile and haul all full tanks over the rocky break to the second sump beyond. Three divers pushed the second sled out 1000m from the rock pile and then set off breathing triple tanks on their backs. They made a further 1000 m before turning for the entrance. Disaster was narrowly avoided as the empty cylinders became so buoyant the divers were pinned against the roof of the cave. Quick thinking enabled the divers to put holes in the buoyant sled and by tying rocks to the cage they were able to limp back to the Rock Pile their air supply desperately low. The three explorers were impossibly tired as they then faced four hours of carrying cylinders over the Rock Pile before they emerged exhausted but elated from a 16.5 hour trip, seven of which were submerged. This set a world record at the time for a penetration into a water filled cave with a single entrance.

1979: Later in the same year, a South Australian team managed the same distance with each diver carrying 5 tanks each with triples on their backs and a tank under each arm. The 4,000 metre continuous swim from the rock plie to the 2,000 metre mark and back lasted 4 hours.

Toad Hall | Photo: Steve Trewavas1982: In September, a team headed by Morrison including South Australians Ron Allum and Peter Rogers, used the new sled technique manufactured from PVC pipe to carry additional dive cylinders and managed 2,500 meters past the Rock Pile in the second sump and emerged into a huge underground lake and dry rock chamber the likes of which had never been seen in Australia. The second dry rock pile, a chamber 10 metres high and 250 metres long was named "Toad Hall" by the divers. The naming of Toad Hall is a secret kept by those who have ventured there. "Many will wonder, but few will know". A third sump was discovered at the farthest end of the 250 metre long Toad Hall rock pile. Read the full report and see the photos here.

1983: In September, a five person team of French cave explorers headed by brothers Frances and Eric Le Guen set a new world record for underwater penetration. The French had bought with them two high powered German Aquazepp underwater scooters and transported enough gear to Toad Hall to mount two separate attempts on the Australian 1982 record by diving solo into the third sump. Eric Le Guen did the first dive and managed a 1460 metres penetration into the third sump from Toad Hall and his brother Frances, on a later dive, managed to push the cave another 90 metres by squeezing through a restriction but was stopped by a second restriction too tight for him to pass with his back mounted tanks. A total of 1550 metres of line was laid in the 3rd sump. On the second dive, the brothers broke the entrance lake surface of the first sump 47 hours after their initial departure. Read the full report and see the photos here.

Chris Brown | Photo: Stefan Eberhard1983: Early in the year before the French divers enter the scene, Ron Allum designed a purpose made sled to mount a dive past Toad Hall, into the third sump of Cocklebiddy. The sled was designed to carry 14 dive cylinders, sleeping gear, food and drinking water, included twin adjustable buoyancy systems that could be controlled by a single diver to maintain the sled at neutral buoyancy. (Note: Drinking water has to be taken on extended trips into Cocklebiddy as the salt content of the cave water is too high for human consumption.) The first prototype sled was manufactured in his shed and had its first trial run in Thorndon Park Reservoir in the outer suburbs of Adelaide and proved to be a success. After the first trial, another 3 sleds were made and plans were made for the next attempt on Cocklebiddy. In October, after the French raid on our cave, a combined Western and South Australian Team made an all out Australian assault on Cocklebiddy to regain their rightful status of being the kings of Cocklebiddy. New comers to the South Australian team were Paul Arbon, Chris Brown, Lester Jerman, George Navas and Dennis Thamm. The plan was for 16 divers with four gear laden sleds to traverse the 1,000 metres in the first sump from the cave entrance lake to the Rock Pile, a 45 minute to one hour swim pushing the sled. Then carry three sleds and gear over the Rock Pile and reassemble. Six divers to push three sleds in the second sump for the 2,500 metre trip from the Rock Pile to Toad Hall, a two and a half to three hour swim. At Toad Hall carry one sled and gear to the third sump and reassemble. Three divers (Hugh Morrison, Ron Allum and Peter Rogers) then to push the sled in the third sump to the restriction at 1,460 metres first reached by French diver Frances Le Guen one month earlier. Leave the sled and swim ahead with each diver wearing three back mounted tanks. At the 1,550 metre mark, Morrison removed his three back mounted tanks, left his two buddies and pushed on ahead solo with a single tank pushed in front of him. He negotiated the restriction at 1,550 metres that stopped the French team, and after passing through a second restriction, managed to push the third sump an additional 240 metres. This point was 1,790 metres under water from Toad Hall and a distance of 5,290 meters of under water passage and a total of 6,240 metres from the cave entrance. A world record dive with a return underwater distance of 10,580 metres. The underground time was 55 hours and the entire expedition was achieved within a space of seven days.

In the excerpt below of an Australian Geographic podcast, Ron Allum gives more insight into the 1983 expedition:

1986: A 5 man team including Paul Arbon, Chris Brown and Dennis Thamm, three of the back up divers from the 1983 Australians expedition, and with the assistance by Brenton Woolcock and Ulrich Hofner, used one of the 1983 expedition sleds and demonstrated that a small team could make the dive to Toad Hall.

Chris Brown with no-mount sled | Photo: Stefan Eberhard1995: An Australian team headed by Chris Brown made an attempt to extend the known length of Cocklebiddy Cave. Team members included Dennis Thamm and Stefan Eberhard, both members of the 1983 expedition, David Doolette, Peter Girdler, Richard McDonald, Tim Payne, Wolf Seidal and Brenton Woolcock. A Channel Nine documentary film crew accompanied the expedition. From previous experience gained from the 1988 Pannikin Plains expedition, the dive plan involved towing sleds with underwater scooters. With one Aquazepp scooter (as used by the French divers in 1983) and two Aquamacks (copies of the Aquazepps made by McDonald), three sleds were towed through the first sump to the Rock Pile accompanied by eight divers. Two sleds, three scooters and a large amount of gear was transported over the Rock Pile. Five divers continued in the second sump and traversed the 2,500 metres to Toad Hall towing the sleds in 1.5 hours, a full hour shorter than swimming a sled. Base camp was set up in Toad Hall for a two day stay. The Aquazepp, eight tanks and a specially designed "no mount" sled were ferried across Toad Hall to the third sump. The no mount sled consisted of an aluminium frame with two tanks strapped inside, two torches mounted at the front, and an inflatable buoyancy bag to make the sled neutrally buoyant and easy to push in front of the diver. The idea of the no mount sled was to negotiate tight restrictions at the end of the cave without the burden of back mounted tanks. After assembling the equipment, Brown with three back mounted, one side mounted and four dive cylinders attached to the Aquazep, took a solo dive into the third sump. At the 1,200 metre mark from Toad Hall, the cave became too low to safely negotiate whilst riding the Aquazepp. The scooter was parked on the floor of the cave and Brown removed the no mount with the 2 tanks inside and continued into the cave whilst breathing off his back tanks. At the 1,550 mark, the furthest point reached by the 1983 French team due to a tight restriction and the point where Hugh Morrison left his buddies and continued on alone with a single tank, Brown removed his three back mounted tanks and continued on through the restriction with his no mount sled and a single side mounted tank. After negotiating two tighter restrictions, he came across the abandoned line reel left by Morrison at the 1,790 metre mark, the furthest point of his penetration on the 1983 expedition. Brown tied one of his two line reels onto Morrisons line reel and continued on into the cave. The tunnel was about 1 metre in diameter and continued on for 20 metres and then the roof slopped down and met the floor and the tunnel abruptly ended. With enough air and 300 metres of line on his two reels this was very frustrating to Brown. He had reached 1,810 metres from Toad Hall and 6,260 metres from the cave entrance of which 5,310 metres was under water. He tied his line off on a rock on the cave floor and looked around. The only continuing passage was on the left going down at a steep grade and was very low and tight about 400mm high and one to one and a half metres wide. Brown dropped his no mount sled, unfastened his side mount tank and continued down this passage for a short distance (approximately five metres) with the single tank. As the passage was not getting any larger he decided to concede and terminate the dive reeling back the five metres of line to the tie off rock. 188 minutes after leaving Toad Hall, Brown arrived back at the third sump lake and completed 60 minutes of decompression obligations before relaying his news to his waiting crew.

Diving Cocklebiddy Cave | Photo: Steve Trewavas1997: Tim Payne and Stefan Eberhard conduct an "alpine style" approach to Cocklebiddy: two divers armed with six cylinders and two scooters each and "an attitude". They dive to Toad Hall and Tim Payne scooters much of the known cave in sump three and explores a couple of side passages on his way back. The team were on site for only one week.

2003: An attempt to extend the cave by a team including push divers Karl Hall and Craig Challen, and support divers Paul Hosie, Paul Boler, and Dave Apperley differed from previous attempts in that rebreathers were now utilised, along with a number of underwater scooters. At approximately the 1,460 metre mark in the third sump beyond Toad Hall, diver Karl Hall removed his rebreather then pushed on with side mount open circuit equipment. During the 52 minutes while Hall was gone, Challen's rebreather began to malfunction and he endured a nerve wracking wait. Hall also had some buoyancy and gas problems and while he reached the end of Brown's tied off line from 1995 he could also only add another five metres. The push divers later claimed no credit for extending the cave and acknowledged all the hard work done in previous dives by Morrison and Brown.

2005: An Australian team of divers including George Yarra, Tania Yarra, Chris Ross, Dean Laffan and Ben Hoskin set up the cave with a large number of scooters and cylinders and conduct multiple runs to Toad Hall. This includes a record when Tania Yarra becomes the first woman to reach Toad Hall and the longest cave dive in Australia by a female.

2006: A small team of divers - Tim Payne, George Yarra, and Stefan Eberhard - utilizing underwater scooters tow sleds (modified originals from the 1983 expedition) of cylinders, scooter batteries, food etc. to Toad Hall where they camp for three days and commence the task of mapping sump three.

2007: The mapping of Cocklebiddy continues with another four day camp at Toad Hall. Tim Payne and George Yarra are joined by Cocklebiddy veteran Chris Brown, Dean Johnson and Mick Quillinan. Much of the mapping of sump three is completed, some new line is laid in side passages, and about one third of sump two is mapped.

Craig Challen | Photo: Geoff Paynter2008: In August Craig Challen and Richard Harris and a support team of seven divers break new ground by extending Browns 1995 line. Using modified rebreathers which could provide 8-10 hours underwater duration, and high tech lithium ion battery packs to extend the running duration of standard one hour scooters to three hours, the two push divers employed a similar dive plan to Hall and Challen in 2003. With Harris waiting it out at the 1460 metre restriction in the third sump, Challen removed his rebreather and forged on with two side mounted cylinders. After breathing down one cylinder, it was also removed and Challen continued on through the tightest parts of the route with one cylinder (fitted with a dual H-valve and its own buoyancy device) pushed in front of him. After tying off his reel to the end of Browns line, Challen continued on for another 120 metres before he was forced to turn back as he reached his gas reserves. The tight twisting tunnel continues. Also of note on this expedition was the set up for the push dive. Divers placed scooters and cylinders through the cave to the lake at the start of sump three, allowing Challen and Harris to undertake the push dive as one major effort involving some 18 hours underground but no camping at Toad Hall. As part of the push dive into sump three, three radiolocation "pingers" were placed in the sump allowing points in the cave to be found from above ground thereby assisting with the three year ongoing mapping project.

George Yarra and Tim Payne preparing a sled | Photo: Tony Richardson2008: In September the mapping of the third sump of Cocklebiddy to the start of Browns 1995 line is completed with a three day camp at Toad Hall. Tim Payne and George Yarra are joined on this trip by Tony Richardson and Mick Quillinan. Sleds are again towed to Toad Hall to transport gas, food, water and sleeping gear. Most of the remainder of sump two is surveyed, but disappointingly the map falls a few hundred metres short of being complete in this 2.5 kilometre long sump. The dry chamber Toad Hall is also mapped.

2009: In a full frontal assault on Cocklebiddy, 14 divers descended on the cave including UK divers Rick Stanton and Leigh Bishop. Four teams conducted dives in sump three including the first two women to dive this sump: Sandy Varin and Agnes Milowka. Sandy reached the 1460m restriction with buddy Dave Bardi. Agnes reached the mid point of Craig Challen's 2008 line (approx 1900m into sump three) giving her the record for the longest cave dive in Australia for a female. Rick Stanton reached the end of Craig Challen's 2008 line and continued on for only a few metres. The passage here is very narrow and silty. Eleven divers in the team reached Toad Hall. Craig Challen (approx. 1800m), John Dalla-Zuanna (1460m) and Richard Harris (approx. 1800m) also made long dives in the third sump. As with the 2008 expedition the lightweight approach with long-range rebreathers and long range lithium powered scooters were pivotal to the success of the dives. Again, as part of the dives into sump three, radiolocation "pingers" were placed in the sump allowing more points in the cave to be found from above ground thereby assisting with the ongoing mapping project. Read the full report here.