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Some of the list members wanted to have a report of BSTD´s exploration efforts in Plura Norway. Here it is, hope you dont get bored it is rather long. Cave diving north of the arctic circle In august 1998 members from the Swedish cave diving group BSTD explored the cave system Plura in north Norway to a maximum depth of 80m (260 feet). Distance penetrated was 1200m and total in water time was over two hours. The team used Gavin design underwater scooters to help propel them trough the ice cold water. This is the deepest and longest cave dive ever done in Scandinavia. The Plura river disappears between the rocks to appear again some 3 kilomaters downstream, this is the site of the Plura cave system. The maximum depth and length of this system is still unknown. In the 1970 a hydro plant was built on the site and the flow have since seized. Before the hydroplant blocked the flow it was so strong that locals have reported a water pillar 3 meters in height at the spring. This suggest that Plura is a very extensive cave system. Plura has been dived quite a bit in the recent years with cave divers Vebjörn karlssen and Nils Eldeby being the ones that has the most dives in the cave. They have also installed the expertly placed main line and explored large parts of the cave. The goal with the BSTD´s expedition was both video documentation and if time allowed also exploration. Exploration of this cave would prove as expected to be quite hazardous and complicated. The ice cold water means that the divers faced the risk of freazing to death in case of a flooded suit. Some of the passages were also extremely silty and narrow. Some of these tunnels were inappropriate for scootering so the fast Gavin scooters could not bee used for parts of the dive. The cold water limited the time the divers could stay immersed so speed was of essence. The Cave The cave begins with a rather narrow entrance. It then widens to a massive tunnel 10 m in height and 20m in with. This tunnel continues for about 450m and has several small side passages, some still unexplored. After 450m the tunnel becomes partially dry and continues an additional 400 meters. At the end of the main tunnel 950m in to the system the cave has collapsed and blocked the passage. At this point a smaller tunnel leads down to deeper regions of the cave. This smaller tunnel is winding down and gets smaller and smaller. Mounds of silt rests on the floor and in some of the tightes restrictions avoiding silt up is difficult. After about 100m the passage widens up to a big room. At one end of the room a huge tunnel leads down, slowly going deeper. This tunnel begins at 25m depth and the end is unknown. This is where the actual exploration took part. Previously explored to 57m BSTD would attempt to push the line deeper and further in to the mountain. The plan There were several logistical problems to bee solved to conduct this dive as safe as possible. The team new that the deep tunnel was at least 60m . Any diving deeper than 40m reacquires Trimix. The depth of the passages leading to the deep tunnel was only 34 meters. A dive plan that was both safe and as simple as possible was required. The plan was to use a single stage bottle for the entire 950m long main passage and return. A mixture of 30% oxygen and balanced nitrogen was chosen. The use of a stage bottle rather than breathing the back gas would enable the divers to explore the deep tunnel with a completely full gas supply in the twin 15 liter tanks. Breathing Nitrox on the shallow part of the dive also gave them an edge on decompression. The back Tanks was filled with 16/45 Trimix and the maximum depth of the dive was set to 80 meters. Speed was of out most importance as the diver could only endure a limited time in the water. No setup divers qualified or equipped to carry decogas in to the deep part of the system was available nor did the push team have time to do set up dives themselves. This meant that the push team had to transport the deco gas on the same dive. To improve speed and simplicity a single 7 liter deco bottle containing pure oxygen was carried. The deep parts of the deco were to bee performed on the back gas. The dive Everything went as planned on the way in to the deep section. The scooters where left before the restrictions at the end of the main passage. The Oxygen bottles where left on 9 meters and the divers carefully made there way down towards the deep tunnel trying there out most to avoid stirring up the silt. Some of the restrictions where so small that they had to squeeze trough. Finally in the big room the divers started down the deep tunnel adding line as they went. The tunnel remained big and slowly went deeper and deeper. At some stages the floor was covered with small stones similar to aquarium stone. The visibility was unlimited and huge boulders were strayed around the floor. This was a truly impressive sight. After a swim of over 200m the divers approached the planed max depth of 80 meters. At this point the tunnel seemed to level out and not increase in depth. No signs of the tunnel getting smaller was seen. Indicating that the tunnel continues a lot longer. The line was tied off and the divers slowly commenced the exit. Approaching the big room large puffs of silt came from the roof completely ruining the visibility. At a quick glance it looked like rocks falling from the ceiling. This was however probably caused by heavy rain fall on the surface. The team proceeded by touch contact being careful not to lose the line. The rest of the Trimix dive was uneventful, everything went as planned and the relatively short deco was carried out with no problems. A serious problem On the way out 10 minutes from the exit one of the divers managed to rip a hole in the drysuit. A sharp stone had cut a large hole. The suit flooded almost immediately. A human will not survive for a very long time in 5 C cold water. Expected time of survival in this temperature was between 10 and 30 min. Luckily the diver was using a DUI thinsulate undergarment witch is designed to keep some of the warmth even when wet.. This proved to help keeping the diver a little warmer. The unlucky diver managed to get out without any serious damage. A slight hypothermia was all. The future BSTD plans to return next year for a serious exploration effort. This was only a reconancense. What limits the exploration is the cold water. The maximum time one can endure in this temperature is probably about 3 hours. On these dives the divers spent 2 h and 30 minutes. Members of the team was: Roger Johansson Johan Berggren Mikael Ollevik Thomas Mattisson Scarlett Andersson Trimix divers: Sigmund lundgren Richard Lundgrten Ingemar Lundgren Fredrik Skogh A big thanks to Vebjörn Karlsson and Nils Eldeby Text Ingemar Lundgren -- Send mail for the `techdiver' mailing list to `techdiver@aquanaut.com'. Send subscribe/unsubscribe requests to `techdiver-request@aquanaut.com'.
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