DAXING SPRING LIES IN a beautiful setting. Just metres from a road, it affords easy access to the water.
The surface lake is more than 100m long and perhaps 30m wide, and in this expanse of sub-tropical 21-22°C water three or more openings lead down into the murky depths.
Between these holes the water is generally more than 10m deep, with sheer rocky sides and a sandy bottom. Despite the milky tinge to the water daylight reaches the floor here, so no light is required.
Our Chinese friends busy themselves practising a variety of in-water skills. Visibility in this daylight zone feels like 6m, but as I drop between the narrowing walls of a steeply descending tunnel I feel the need to turn my head-light on.
Suddenly, with backscatter, visibility is reduced to about 4m. The place feels oppressive. A thin technical line, slightly discoloured after many months’ immersion, gives me something on which to keep a very close eye.
I make a slow controlled descent to about 40m, gaining the impression that down here the place is big. There are dark voids all around, and losing the line would be more than embarrassing.
After cruising around the lake and probing various holes for more than an hour, I get the feeling that down in these depths is a veritable labyrinth to be explored. This is not an area of big clearwater tunnels like Florida – this is a more serious kettle of fish.
When I had stepped off the plane I had still been wondering if this was all too good to be true. My all-expenses-paid trip to China had been arranged by email by people I had yet to meet, and details remained sketchy.
I was alone in Nanning Airport in the south-eastern Guangxi province, an area I hadn’t visited for 28 years, and was feeling slightly nervous.

I HAD BEEN INVITED TO PARTICIPATE in the opening of a new dive-centre that was almost certainly the first of its kind in China, located in the neighbouring city of Du’An.
An attractive young lady had walked over to greet me, and my anxieties had melted away as I was ushered to the bar to meet a small group of fellow-invitees. I recognised Curt Bowen, one of the leading technical divers in the USA – we had met a few weeks earlier at a dive conference in Antwerp.
The other two were French. I didn’t know Sebastian Lissarrague, who had initiated the current round of exploratory cave-diving activities in Du’an, but his companion I knew by reputation.
Pascal Bernabe is a highly accomplished cave-diver, although his most audacious undertaking was a 2008 world depth record dive of 330m, carried out on open circuit off Corsica.
There were eight guests in total. The appointed organiser of the event, Pierre Deseigne, was already in Du’An along with the Australian Richard “Harry” Harris and film-maker Nathalie Lasselin from Canada. A leading technical diver from Finland, Mia Pietikainen, was on her way.
Clearly I would be rubbing shoulders with some of the world’s most experienced technical-diving practitioners – this should be one hell of a week.

I HAD NOT VISITED THE CITY of Du’An before, but in 1985 I spent the best part of a month in the limestone country 170 miles to the north-east, based at Guilin. This whole area, stretching down towards the Vietnamese border, is renowned for its “cone karst”, spectacular pyramidal towers of limestone that extend as far as the eye can see and beyond.
This is the world’s largest single karst region. The towers and cones are the backdrop for so much traditional Chinese painting that inevitably the area features large on the tourist itinerary. I had never seen anything quite like this scenery, before or since.
Back in the early 1980s the Chinese were keen to establish positive international relations and, given Western expertise in all aspects of cave-exploration and scientific study, had invited a British team to help progress their fledgling skills in this field.
As such, 1985’s had been a landmark expedition, with more than 18 miles of passage surveyed in a number of different caves. I had carried out the very first cave-diving operation in China, when we tackled the terminal downstream sump in the headwaters of the lengthy Guan Yan system.
Despite the limitations of the equipment available at the time, an impressive clean-washed 30m-deep tunnel was successfully passed to reveal a short dry continuation beyond. History had been made.
Two years later, another British team had visited the flooded caves near Du’An. Their dives established that the sites were plentiful, very big and deep.
A number of places were dived to 70m depth on air, but it was clear that continued exploration would need to wait until technology advanced.
The years had passed. It was not until 2010 that a Frenchman, Jean Botazzi, persuaded a group of his countrymen to mount an expedition.
Two trips resulted, and in 2012 lead-diver Pierre Deseigne established a Chinese depth record with a descent to 121m in Daxing Spring.
The Chinese had by now roughly established the extent of the huge flooded underground network. They also realised that diving itself would prove a tourist attraction, especially among the technical fraternity.
A project was launched to capitalise on the unique features of the area. It would be designated a “Geopark”, with a dive-centre set up in the city to cater for divers from around the world.
It was a two-hour journey from the airport to Du’an. As we arrived work was still frantically underway to set the final touches to the dive-centre, and we learned that the opening ceremony was scheduled for the end of the week.
The all-important diving equipment was ready and waiting; facilities for gas-filling were set up. The hotel was fabulous, the food excellent and we were treated like royalty. We had decent vehicles and drivers to get to the dive-sites and translators to ensure that everything ran smoothly.
The authorities were determined to create the right impression.

DIVING HAD BEGUN THE DAY AFTER OUR ARRIVAL as, together with some Chinese divers and an unprecedented entourage of photographers and journalists, we had paid that first visit to Daxing Spring.
We couldn’t all dive the same cave at the same time, so day two saw the emergence of two teams.
I accompany Harry Harris and film-maker Nathalie to Lie Nei Cave. Harry is weeks away from a major expedition to the Pearce Resurgence in South Island, New Zealand.
The Pearce, with 6° water, strong flow and current depth of 220m, is serious – Harry is clearly at the top of his game.
Lie Nei Cave is a discreet site at the edge of a small village, overshadowed by a huge, well-vegetated tower of limestone. A flight of stone steps leads down into the water and the pathway can be seen leading away into the depths.
Low crags surround the small pool, and a host of young children quickly take up position, curious as to what we strange people are up to. Everywhere we go during the week journalists, photographers and film-crews appear, while the local inhabitants are clearly bemused by the strange activity.
Lie Nei is very different from the spacious Daxing, but it is soon apparent that the visibility is much the same - about 4m.
Harry dons his rebreather and, after posing briefly for the inevitable photocalls above and then below water, disappears into a descending tunnel. The stone steps finish at a depth of 6m, so clearly this is the level to which the water falls in the dry season.
We follow a comfortably large tunnel for a short distance before the floor falls away, lost to view. Below 15m depth the line clings somewhat precariously against the cave roof, which angles down ever more steeply.
Diving open-circuit, it is evident that silt is being displaced. Photography is not easy under these conditions, and with Harry still exploring somewhere far below, Nathalie and I retire back to the shallows. In the event, Harry’s two-and-a-half-hour solo dive takes him down to 107m depth, leaving the cave wide open.

IT’S DAY THREE, AND WE’RE AT TUN LEI, a remote site deep in the cone karst. The hole itself is impossible to access without a ladder, as it is ringed with sheer-sided and undercut rock faces.
Our hosts come up with a rigid 4m-long bamboo structure and some rope. Equipment is then lowered and we kit up while floating over the relatively clear, deep water. This place has a lovely feel, but life would be a lot easier if some form of floating platform was installed.
Visibility is of the order of 6m or more, a pleasant change from the other sites we have seen. Below the surface, a slope of rocks and debris leads steeply into the depths. Tun Lie is evidently a huge chamber under water, perhaps 40m or more across.
At about 40m depth the walls funnel in and a narrowing passage just a few metres wide leads steeply down to a terminus at 67m depth. This fine dive is the only one we do that leads to an “end”. Presumably the visibility is better here, because the site does not sit on an active flow of water.
The other team is also showing its colours. Its leader Pascal, diving open-circuit while his buddy Mia uses a rebreather, returns to Daxing and descends to 130m depth.
In the following days deep dives are also undertaken at Jellyfish Cave. On one of these a French trimix bottle, lost two years previously, is recovered from 100m depth.
This site is the location for Du’an Dive Centre’s grand opening ceremony. There are four separate holes there, all seemingly in excess of 100m deep (some holes in the area have been plumbed to depths in excess of 150m).
This is a vast area of subterranean drainage, and the scores of cave-diving sites identified to date are in reality “windows” to far deeper active conduits, providing generations of explorers with years of exciting exploration.
Finding those tunnels and following them is, however, going to be challenging. We know that flowing water that makes a brief appearance at the surface at Daxing Spring finally enters the Red River 22 miles distant.

NONE OF US WILL EVER FORGET THE DAY of the ceremony. Jellyfish Hole provides a spectacular setting as hundreds of people turn up to listen to the speeches and savour the moment. I act as delegate for the international diving group.
The formalities are followed by a lavish display of Chinese tradition and spectacular fireworks before we return to the city for a second round of festivities.
The invited divers give individual talks in the afternoon, and the day reaches a climax with a show in the city square, where thousands of people form an audience primed for our arrival.
We are feted like celebrities, and are later invited onstage to have our photographs taken with the performers.
From the scale of the week-long exercise, it’s clear that the Chinese recognise that they have something very special at Du’An.
The Guangxi Du’An Underground River National Geopark has received national recognition, and in two years’ time the hope is that the designation will be international.
The pace of development throughout China is rapid, nowhere more so than Du’An. We eight divers were lucky to have been invited at the outset of this project, but it will be Chinese divers who take up the gauntlet of exploration.