Brazil: the very word stirs the imagination. Images of carnival and coffee, overshadowed by Amazonian rain forest with dense, steaming jungle, crocodiles and giant anacondas.
     This is a little-travelled, unknown and exciting area. Warm, clear waters are always attractive but when they contain unique scenery in an area seemingly never before dived by UK divers, they are doubly so.
     Last summer three of us set out to reconnoitre the remote Bonito area in the state of Mato Grosso do Sul, hundreds of miles west of the capital Brasilia and close to the borders of Bolivia and Paraguay. There can be few places further from the sea, and the nearest recompression chamber lies at Sao Paulo, 750 miles away.
     Realistically it takes two days to get there from the UK, via the provincial capital and the nearest airport at Campo Grande. Travelling by road from Sao Paulos intercontinental airport takes 14-20 hours.
     Nothing could have prepared us for this South American odyssey. On the three-hour drive from Campo Grande we could see that the land here is incredibly flat and, largely cleared of jungle, has been given over to ranching.
     Cattle are everywhere, roaming freely in a coarse variety of pampas grass. Few people speak English, yet everyone we met, police included, was friendly and helpful.

beautiful business
     Bonito means beautiful and eco-tourism is big business here. With its monkeys, ant-eaters, crocodiles, snakes, toucans and macaws, together with unbelievable fish life, this is a photographers paradise. The area also provides an excellent base for exploring the Pantanal, the largest area of swampland in the world outside the Amazon basin.
     Most visitors come to swim, canoe, kayak and raft, because many of the rivers are fed by some of the clearest limestone springs on the planet, often rising from large, deep flooded caves. South American diving is largely undocumented but Bonito is Brazils primary cavern and cave-diving area.
     July, August and September, winter in the southern hemisphere, is the preferred season for this activity. Given the latitude, winter in Bonito is hot. Temperatures were in the upper 20s during the day, though it can get cool at night.
     Water temperature is blissful, never less than the low 20s. Neither temperature nor rainfall significantly affects activity in the rivers in winter, which provides even the most experienced diver with a stunning insight to a tropical wonderland.
     You can scuba-dive in the rivers or take part in the hugely popular tours in which you enter the water near the spring and, equipped with wetsuit, buoyancy aid, mask and snorkel, simply drift along in a small party led by a guide.
     In the interests of conservation no fins are worn, which does compromise manoeuvrability. However, I cant begin to list the fabulous variety of fish seen on the Rio Da Prata tour.
     We also saw upwellings of water from the underlying limestone rocks. These often took the form of a sand-boil, and we could dive down and play amid the limestone equivalent of an underwater volcanic eruption. This tour must rate among the most leisurely, fascinating and enjoyable underwater experiences of all time - and virtually all of it in less than 1.5m of water!
     For reasons best known to itself, the government had effectively closed all Brazils cave-diving sites the previous year. But our host was Gilberto Menezes, the countrys foremost cave-diver, and he spent hours arranging the necessary permissions on our behalf with the department responsible, IBAMA. The restrictions are not conducive to relaxed holiday diving and we hope they will eventually be eased.

mystery of the cones
As most diving is undertaken directly from daylight, conventional techniques have been adopted, based closely on the Florida style of diving. Our first foray was to Mimoso Cave, where Gilberto began his cave-diving in 1994. It was photographs of this site that had made us want to visit Brazil.
     This enormous cave appears to be a relic of some ancient fossil network, the major part of which is now blocked or inaccessible. Divers can explore about 200m of passage to a terminal depth of 40m. The dive base lay at the foot of a steep boulder slope, overhung by a high, arched ceiling adorned with enormous stalactites. This majestic setting of the entrance hallway was a mere taster of what was to follow.
     A 25m-long lake dips gradually to an enormous tunnel. Arrays of stalactites up to 3m long are draped in clusters from the ceiling.
     The tunnel passes an obvious junction away down to the left, at about 70m, then rises to a substantial air pocket about 100m from dive base. The air in this chamber is very low in oxygen, so divers are advised not to remove their regulators.
     Descending back down the slope, a glimmer of daylight almost immediately appears. Reaching the junction, the passage on the right leads within 10m to an amazing area of stalagmites.
     This is the start of the area known as the Cones, a unique group of rock formations the origin of which is hotly debated, as they do not seem to be associated with conventional dripstone. This 40m-deep cave must rate as the most superb dive in Brazil.
     The caves of this area are generally big and clear, but the most surprising feature is their depth. The second days diving was to a cave called Ceita Core, or Land of My Children. Here we found a strong spring of the clearest water imaginable issuing from a small cave entrance. The cave starts modestly, dropping through a diminutive chamber to a constriction.
     Equipped for basic side-mounting, this was just a simple swimthrough, but watching the careful manoeuvrings of those with back mounts immediately generated feelings of concern and immense respect for what had been achieved here.

the big squeeze
At 20m deep, the cave opens to a narrow fissure which plummets away into the depths. We were diving on air and stopped at 40m. Gilberto played the narrow beam of his laser-like HID light to and fro and gestured that we were looking down to 80m. Below this there is a further constriction, beyond which Gilberto had been confronted by an even greater squeeze at 155m depth. With a sense of privilege and awe we gazed into the cobalt waters far below.
     Day three took us to a site no less impressive, aptly named Mysterious Lagoon. The approach entailed the usual drive of about an hour along dusty gravel tracks and monotonous flat terrain. Eventually we reached a large cluster of trees amid the endless expanse of ranchland.
     Here in the jungle you might expect to find swamps and crocodiles, but as we moved between the trees a huge chasm, 50m or more deep, suddenly opened before us.
     At the bottom lay a patch of turquoise water, some 100m long by 50m wide. Darker patches indicated the positions of two underwater shafts. The full story of Gilbertos exploration here would merit an article in itself, an unbelievable adventure to more than 120m depth using only air. His account of becoming wedged in a constriction at this depth is hair-raising.
     After a miraculous escape and a bend, he was, he says, reborn after this event and went on to train using mixed gas with Tom Mount in Florida. Within a year he returned to Mysterious Lagoon and progressed the exploration to the current terminal depth of 220m.
     Gilbertos approach to deep exploration is marked by focus, professionalism and extreme caution. Just a short time before our visit, he reached a depth of 274m at Blue Lake, in a neighbouring state, the third deepest cave dive in the world.

ancient and sinister
Mysterious Lagoon is now a commercial dive site, with an aerial ropeway for transporting dive-gear to and from the chasm, a stepped walkway for access and a platform at the waters edge. This unusual site is best regarded as some form of window or shaft leading to an ancient network of cave tunnels somewhere far beneath. The water lacks the extreme clarity of springs such as Ceita Core, but visibility is well in excess of 50m.
     I felt uneasy as I floated out and settled quietly into the depths. The almost sinister feel to this place was reinforced when I talked with the owner later that day. A few years ago, he told me, a noise like thunder had emitted from the hole. Inspection indicated no rock collapse or fall of trees but the surface of the normally placid water was said to be seen rippling.
     Clearly some deep-seated hydrological event had occurred which, with the present state of our knowledge, defies any simple explanation.
     The following day we visited Formosa Springs, a site Gilberto had been exploring. Two beautifully sculpted springs lie about 50m apart, fed by the same water-source, and connect a few hundred metres from the entrance at a depth of 60m.
     Beyond this point Gilberto had progressed to more than 400m, passing an elbow at nearly 90m depth to locate a large and ascending chamber beyond.

butterfly trail
A 4x4 is helpful on the long off-road approach to the springs. The site is remote, surrounded by dense jungle and inhabited by just about every winged creature, particularly butterflies.
     Visibility in the water was poor, no more than 10-12m, but the site made for superb diving, being spacious, well-lined and inhabited by several species of fish.
     We took in a wealth of sites over the following days and returned to Formosa for the final exploration. The previous week Gilberto had undertaken many solo operations in preparation for the next advance, installing more than 16 sets of stage and decompression bottles at prearranged points.
     He entered the water at 9am, parked his scooter at 83m depth, some 400m into the cave, and continued by swimming.
     Beyond a restriction at 90m he soon reached his previous 450m limit and rose into a vast room. The way forward was uncertain and ultimately he rose to 18m, where an intricate maze of silty passages and very poor visibility confronted him.
     A search for the main flow proved fruitless, and with time and visibility against him, he was forced to head back.
     Unfortunately his scooter turned out to be flooded, and he had to abandon it and swim out. After more than six hours in the water he surfaced in excellent humour, quietly resigned to the setback. Knowledge gained on such dives is invaluable and, diving at such extreme depth, one can only expect to advance a short way on any one operation.

margates at Fernando de Noronha play a shadow game with divers
Looking up to the entrance from the chamber of Ceita Core
Top Brazilian cave-diver Gilberto Menezes prepares to delve further into Formosa Springs
Stalactites in the tunnel at Mimoso Cave
Diving in Formosa Spring
Phillip Dotchon, Martyn Farr and Pat Cronin in the pool at Formosa
River-drift experience in the Rio da Prata
Stopping to play in a sand-boil in the riverbed
The massive Gruta Do Lago Azul formation - the person at the foot of the steps gives an idea of its scale
Crocodiles are found just about wherever there is water


GETTING THERE Varig Airlines flies from the UK to Sao Paulo and Rio de Janeiro, with connecting flights to Salvador or Sao Paolo. A return flight from London Gatwick to Rio will cost from £560. Brazil is a big country to get around, despite its excellent infrastructure. Consider flying from site to site if time is limited.
DIVING:Bonito - Sub Mundo Dive, (0055) 67 255 2040, www.sub mundo.com.br. Fernando de Noronha - Atlantis Divers, 84 206 8840, www.atlantisnoronha.com.br; Aguas Claras, 84 3619 1225, www.aguasclaras-fn.com.br; Noronha Divers, 81 3619 1112; Costa do Saiupe - SuperClubs Breezes, 71 463 1502, www.superclubs.com; Buzios - Casamar Diving, 24 623 1302; Arraial do Cabo - PL Divers, 24 2622 1033; Sandmar Nautica, 24 622 1356
ACCOMODATION:Mid-price hotels and pousadas (B&B). Rio de Janeiro - Luxor Regente, (0055) 21 523 4121; Winsor Palace, 21 548 0098; Fernando de Noronha (book well in advance) - Pousada Agul-hao, 81 3619 1368; Dois Irmaos, 81 3619 1301; Salvador - Sofitel Hotel, 71 374 8500; Buzios - Hotel El Cazar, 24 623 1620; Arraial do Cabo - Genesis Hotel, 24 622 2278
FURTHER INFORMATION: Rio de Janeiro, Dept of Tourism (0055) 21 2544 7175, e-mail: miriam@turisrio.rj.gov.br, Fernando de Noronha, Ecotourism Department 81 3619 1378; Bahiatursa, 71 370 8400; Bahia Adventure 71 464 2525

Diving in Brazil with Denise Mattia