Many people regard cave diving as the most dangerous sporting activity one can choose to pursue. It is an activity which requires the most high-tech equipment in order to explore the increasingly hazardous unknowns. Extensive training, experience and preparation are essential for these divers to survive the depth or distances that are covered. Cocklebiddy Cave in Australia has the longest known underwater series of passages covered by man at 5290m however its depth barely reaches more than 30m. Nacimiento del Rio Mante in Mexico by contrast attains a staggering depth record of 267m.
Early attempts at cave diving were restricted to free-dives through relatively shallow sumps. The first success recorded was by a Frenchman diving in a Pyrenean Cave in 1922. British cave exploration was pioneered by H.E. Balch and Dr. E. Baker. From 1901 they explored many caves on the Mendip hills, the home of British caving. By 1921 they had reached sump 1 of Swildon’s Hole at Priddy, but it was not until 1934 that a serious attempt was made by Graham Balcombe and Jack Sheppard to try and conquer this under-water passage. Frequent efforts failed with home-made equipment using hosepipes. The respirator and diving suit were improved by Sheppard with the cold water causing great discomfort to the otherwise unprotected cavers. On the 4th October 1936 an extensive cave party saw the first success by Jack Sheppard to dive sump 1. Its relatively short distance soon dispensed with diving gear and became a free-dive. Greater adventures nevertheless were already being planned. For many years it was known swallets on the Mendips fed Wookey Hole. Exploration was the only means of finding if these could be connected.
Balcombe and Sheppard realised that their only means of discovering the unknown passages of the Wookey Hole Caves was by a self-contained respiratory unit. An application for the loan of equipment from the Siebe Gorman Company (submarine and safety engineers) was accepted and they took delivery of several sets of Standard Diving Equipment. It comprised a large metal helmet, lead weights, suit and air tubes with pump. Many months of training were carried out at the Minieries Pool, Priddy, prior to the first dive. Before the leat fed the mill and the water controlled by the sluice at the exit of the cave, Chamber 4 was easily accessed. Here human bones and pottery were found in 1823 and an official excavation of a Roman burial site was carried out in 1973-76. The third chamber with its large bank was to provide the ideal site for the series of dives to follow.
Six divers in total were involved Graham Balcombe (Ascot), Wyndham Harris (Wells), Frank Frost (Bristol), Bill Bufton (Exeter), Bill Tucknott (Wells) and Penelope Powell (Wookey Hole). ‘Mossy’ Powell as she was regularly known attended the Minieries training sessions, helping with the washing and storing of the diving equipment. Sheppard was to be part of the initial diving party but with his departure the five male members of the party deliberated over who should be selected to fill his place. From the large party of volunteers involved in the operation it was difficult to discriminate and the best way to resolve the matter was to give the place to a woman. Her role in the dive was to act as the support or ‘second’ diver to Balcombe.
With the caves becoming a popular tourist attraction all the dives had to take place at night and on weekends. The 13-14th July 1935 saw Balcombe and Powell enter the green world of the River Axe. Their first expedition reached the already known Chamber 4. By the 4th August the pair had reached Chamber 6 and on the 31st August Chamber 7, a substantial distance from base with the equipment used. Further progress which would have been particularly difficult due to the length and awkwardness of the air tubes trailing back to the pump, was not stopped by the divers but by the villagers and the mill owners, all having to use the river for their supply of water which by now had become contaminated by the disturbed silt. The B.B.C. had shown some considerable interest in the proceedings of the expedition and the efforts of the two lead divers were broadcast to the nation as they progressed to Chamber 6 on 17th August.
Diving did not resume until after the war. The newly formed Cave Diving Group led by Balcombe and Sheppard reached the eighth chamber with Operation Janus in 1947 using self-contained respirators. A year later with Operation Avanti success was made with the finding of Chamber 9. From this time on Chamber 9 became the forward base, 92 metres from Chamber 3.
1949 saw the first British fatality in cave diving. Operation Innominate sought to investigate Chambers 10-11. Longer expeditions required more divers with experience. Gordon Marriott was an ex-Royal Marine of exceptional skill and achievement in open water diving. In needing another diver Balcombe saw his skill as being a major asset. Exploration to Chamber 11 was uneventful. The group of divers on their return decided to split, two decided to take the short dive back to Chamber 3 while Marriott and supporter opted for the longer dive via the ‘loop’ from Chamber 9. At Chamber 6 Marriott made an unexplained error, ran out of oxygen and then dropped his reserve cylinder. His body was not found in time and artificial respiration was ineffective.
Deep diving cannot be achieved with cylinders containing oxygen alone. Mixtures of Oxygen and Nitrogen were first used to progress further than Chamber 11 in 1955. Soon Chamber 13 was discovered and in subsequent years with similar apparatus Chamber 15 was reached at a depth of twenty-three metres. The year 1970 saw a big push by the renowned Rob Parker to Chamber 22. During the years 1976-82 Martyn Farr discovered Chamber 25 and pursued its depth to 60m, thus setting a new British cave diving depth record.
Further attempts were mounted to try and break Chamber 25 and continue to the elusive 26. After a lapse of three years Rob Parker began his intrepid descent down the deep underwater cavern. Using a mixture of 36% Helium, 19.5% Oxygen and 44.5% Nitrogen, Parker descended to a depth of 68m, only to find the way forward to be impossible due to strong water currents and an extremely tight squeeze. After 50 years at Wookey Hole, caving diving had reached its furthest point, 1072m from the new diving base of Chamber 9.
D. Hudsmith