A few months ago I received a letter from the American caver Bill Stone. Bill was interested about diving in siphons of Krubera Cave.

He needed this information for the foreword to a new book by Martin Farah. Of course, Bill was primarily interested in the deepest and longest siphons of Krubera Cave. However, while answering Bill, I myself became interested in knowing total number of siphons in the Krubera Cave. By counting, I was even more surprised. It turned out that there are 17 known to date siphons in the cave.

14 siphons are in the Osnovnaya (Main) branch and 3 siphons are in the Nekuybyshevskaya branch. Some siphons are located in the tributaries of the cave. Some siphons are not passed so far, and there are siphons in which no one even submerged. Siphon numbering in the cave somehow did not caught on, but most of the siphons have their own names. In the compiled list, siphons are numbered in chronological order according to the start of their studies.

S1. Bermudy Siphon, or C1. The Osnovnaya branch, depth -1440 meters

It was the first siphon discovered by cavers in the Krubera Cave. It happened in January 2001, during an expedition of UkrSA. Along with the siphon a bypass of it was found. It allowed cavers to reach a record depth for that time of -1710 meters. Oleg Klimchuk was the first one to plunge and dive it through. It was in August 2003 during the expedition of the Kiev Speleological Club and team Cavex. Completely separate part of the cave was discovered behind the siphon. It later turned out to be the deepest. Pioneers defined parameters of siphon as 7/-2. In fact, it was much more modest. Also, with the use of engineering methods, siphon was simplified for passage (UkrSA expeditions of August and October 2004). As of today, the parameters of the siphon are 2/-1. Siphon is usually passed without an aqualung. It is equipped with stationary 10mm lifeline and rope to drag loads.

The world's deepest Krubera Voronya Cave. Bermudy Siphon

YURIY KASYAN. Osnovnaya branch. Depth -1440 meters. Bermudy Siphon.

The world's deepest Krubera Voronya Cave. Bermudy Siphon

YURIY KASYAN. Osnovnaya branch. Depth -1440 meters. Bermudy Siphon.

Video: Siphon at the depth -1440 meters. Overcomes breathhold

Krubera Voronya Cave vertical profile showing the location of siphons

Krubera Voronya Cave vertical profile showing the location of siphons

S2. Siphon in the tributary that flows into the Ykrainskaya Noch (Ukrainian Night) chamber. The Osnovnaya branch, depth of -1650 meters

The tributary was discovered during the January expedition of the UkrSA in 2001. From a window in the wall of the well flowed a stream at a rate similar to that of a stream flowing from the Bermudy siphon. Therefore, there was an erroneous assumption that this is the same water.

The world's deepest Krubera Voronya Cave. Siphon in the tributary that flows into the Ykrainskaya Noch chamber

YURIY KASYAN. Osnovnaya branch. Depth -1650 meters. Siphon in the tributary that flows into the Ykrainskaya Noch chamber.

The world's deepest Krubera Voronya Cave. Siphon in the tributary that flows into the Ykrainskaya Noch chamber

YURIY KASYAN. Osnovnaya branch. Depth -1650 meters. Siphon in the tributary that flows into the Ykrainskaya Noch (Ukrainian Night) chamber.

However, during the summer expedition in 2001, it was found that the flow rates are very different. In August 2001, Yuri Kasian climbed the window in the well, and entered the tributary with length of about 50 meters. Further way was barred by the siphon. In August 2008 (UkrSA expedition) water level in the siphon was lowered with the help of plumbing hoses, and Yuri Kasian swimmed it through. Siphon turned out to be 3 meters long. Also, behind the wall of a small flooded room, a siphon continuation was discovered. Yuri Kasian made an exploratory dive to several meters. Siphon had continuation and the course was going down. To this day, the siphon had never been passed.

The world's deepest Krubera Voronya Cave. Siphon in the tributary that flows into the Ykrainskaya Noch chamber

YURIY KASYAN. Osnovnaya branch. Depth -1650 meters. Siphon in the tributary that flows into the Ykrainskaya Noch (Ukrainian Night) chamber.

The world's deepest Krubera Voronya Cave. Siphon in the tributary that flows into the Ykrainskaya Noch chamber

YURIY KASYAN. Osnovnaya branch. Depth -1650 meters. Siphon in the tributary that flows into the Ykrainskaya Noch (Ukrainian Night) chamber.

S3. Goluboe Ozero (Blue Lake) Siphon. The Osnovnaya branch, depth of -1783 meters

Goluboe Ozero siphon was discovered by Cavex team in July 2004. In August 2004, Gennady Samokhin (UkrSA expedition) plunged into the siphon. At a depth of 10 meters at the bend, siphon was filled with cemented stones, which didn’t allow Samokhin to pass it. Later it turned out that the level of the siphon can greatly vary depending on the water flow rate in the creek. Behind the siphon there is an upward well with height of approximately 7 meters, but the water is discharged through the through-passage in the rock. The diameter of the channel is about 10 cm. When the flow exceeds the capacity of the channel, the water level rises and completely floods the upward well, so water starts to flow over its edge. So it turns out that the depth of the siphon can vary from 3 to 10 meters. During one of the Cavex expeditions, Oleg Klimchuk managed to dive through the Goluboe Ozero siphon during low water and climb the upward well. Parameters of the Goluboe Ozero siphon during low water are 10/-3. In general, the siphon is fairly spacious, but the passage is complicated due to local clamping in the bend. Equipped with stationary 10mm lifeline.

The world's deepest Krubera Voronya Cave. Goluboe Ozero Siphon

YURIY KASYAN. Osnovnaya branch. Depth -1785 meters. Goluboe Ozero Siphon.

The world's deepest Krubera Voronya Cave. Goluboe Ozero Siphon

YURIY KASYAN. Osnovnaya branch. Depth -1785 meters. Goluboe Ozero Siphon.

The world's deepest Krubera Voronya Cave. Goluboe Ozero Siphon

YURIY KASYAN. Osnovnaya branch. Depth -1785 meters. Goluboe Ozero Siphon.

S4. Maluk (Kid) Siphon. The Osnovnaya branch, Bolshaya Razvilka (Large Fork) district, depth of -1790 meters

In August 2004 (UkrSA expedition) several entrances to the siphons were discovered in the Bolshaya Razvilka district. In February 2005, Nikolai Soloviev (UkrSA expedition) dived through one of the siphons and discovered a link between the two entrances. Both entrances were in a known part of the cave. Siphon was called Maluk due to its modest parameters of 5/-2.

The world's deepest Krubera Voronya Cave. Flooding. The flow of water to siphon Maluk

KONSTANTIN STOILOV. Osnovnaya branch. Depth -1790 meters.
Flooding. The flow of water to siphon Maluk.

S5. Siphon at the mark of -1840 meters. The Osnovnaya branch

This siphon stopped cavers in August 2004 (UkrSA expedition). The expedition ended, and the dive into the siphon hadn’t been made. In October 2004 (UkrSA expedition) the bypass of the siphon was found, so there was no need to dive anymore. To this day, the siphon is still not passed. Based on the survey data, an assumption can be made that the length of the siphon is about 10 meters.

S6. Kvitochka (Flower) Siphon. The Osnovnaya branch, depth of -1980 meters

The siphon was discovered in October 2004 (UkrSA expedition). In February 2005, Nikolai Soloviev (UkrSA expedition) dived through the siphon and found continuation of the cave. Siphon parameters are 10/-3. The siphon is equipped with a stationary 10 mm lifeline. Passing does not require use of fins. Cavers from Cavex team were trying to bypass the siphon during several consecutive expeditions, but failed to do so. If necessary, the water level in the siphon can be reduced with the use of flexible hoses, so the passing won’t require aculungs. In 2006 (UkrSA expedition) such an attempt was made and it was successful.

The world's deepest Krubera Voronya Cave. Kvitochka Siphon

YURIY KASYAN. Osnovnaya branch. Depth -1980 meters. Kvitochka Siphon.

The world's deepest Krubera Voronya Cave. Kvitochka Siphon

YURIY KASYAN. Osnovnaya branch. Depth -1980 meters. Kvitochka Siphon.

Video: Kvitochka Siphon. -1980 meters. Siphon parameters are 10/-3

S7. Podnyr (Dive) Siphon. The Osnovnaya branch, depth of -2010 meters

The siphon was first passed in 2005 by Oleg Klimchuk (Cavex team expedition). Siphon parameters are 2/-1. Equipped with stationary 10mm lifeline. Can be passed without scuba gear.

Video: Podnyr Siphon. Depth of -2010 meters. Siphon parameters are 2/-1. Overcomes breathhold

S8. Unitaz (Toilet) Siphon. The Osnovnaya branch, depth of -2050 meters

The siphon was first passed in 2005 by Oleg Klimchuk (Cavex team expedition).

Unitaz siphon is very difficult to pass, due to narrow bends, for which he received his name. Parameters are 15/-2. UkrSA expedition in 2006 found a bypass of the siphon, which greatly simplified the process of getting to the bottom levels of the cave. Bypass was called Gambit.

S9. Dva Kapitana (Two Captains) Siphon. The Osnovnaya branch, depth of -2144 meters

The world's deepest Krubera Voronya Cave. Dva Kapitana Siphon

Cavex team was the first to reach the siphon in 2005. The first to plunged into the siphon was Gennady Samokhin (UkrSA expedition) in 2006. That plunge was made possible by discovery of Ynitaz siphon bypass. Samokhin unwound 40 meters of lifeline and plunged to the depth of 14 meters. Further passing was prevented by the boulder that was stuck in the middle of the passage. The situation was even more complicated because of one of the cylinder mounted to Samokhin’s back. Oleg Klimchuk (Cavex team) managed to pass the problematic place and dived to the depth of 30 meters. In 2007, divers Gena Samohin and Yura Evdokimov (UkrSA expedition) alternately immersed in Dva Kapitana siphon. Samokhin managed to plunge 45 meters. That is the limit depth for air diving. However, the siphon is not fully passed and has continuation. Several attempts were made by Cavex team, but complex configuration of the siphon and very narrow parts of it prevented the divers from diving deeper than the known part. In 2011, Lithuanian cavers failed to organize a dive into the siphon. After reaching the Dva Kapitana siphon, they were unable to extract the air tanks out of plastic pipe container. In August 2012, Gena Samokhin managed to plunge to the depth of 50.5 meters at length of 140 meters using special breathing mixture. Siphon continues as a narrow slope passage.

Topographic map of the Dva Kapitana Siphon

The world's deepest Krubera Voronya Cave. Topographic map of the Dva Kapitana Siphon

The world's deepest Krubera Voronya Cave. Dva Kapitana Siphon

YURIY KASYAN. Osnovnaya branch. Depth -2144 meters. Approach to the Dva Kapitana Siphon.

The world's deepest Krubera Voronya Cave. Dva Kapitana Siphon

YURIY KASYAN. Osnovnaya branch. Depth -2144 meters. Dva Kapitana Siphon.

The world's deepest Krubera Voronya Cave. Dva Kapitana Siphon

YURIY KASYAN. Osnovnaya branch. Depth -2144 meters. Dva Kapitana Siphon.

The world's deepest Krubera Voronya Cave. Dva Kapitana Siphon

YURIY KASYAN. Osnovnaya branch. Depth -2144 meters. Dva Kapitana Siphon.

Cavex and UkrSA expeditions of different years had seen in the siphon transparent fish about 3 cm long. In 2013 (UkrSA expedition), an attempt was made to catch at least one fish for further study. Unfortunately, that time there was no fish in the siphon.

Video: Dva Kapitana Siphon. August 8, 2012. Surfacing cavediver Gennady Samokhin after record dive. Now the depth of the cave is 2196 meters!

S10. Siphon in the tributary at the beginning of the Collector (Sewer). The Osnovnaya branch, depth of -1710 meters

During the flood in October 2005, water came from the tributary at a rate of about 20 l/s. When there was no prolonged rainfall on the surface, the flow was usually "silent". During the "quiet period" Yuri Kasian climbed into a tributary. Almost immediately further progress was stopped by the siphon. In 2006 (UkrSA expedition) the water level in siphon was lowered by a flexible plastic hose D40 mm, and the cavers passed the tributary of 150 meters in length and 20 meters vertically (hydro technician - Akimov V., scouts - Tregubov A., Kravchuk O.). Further passage was stopped by possible rockslide hanging from the ceiling.

S11. La Siphon. The Osnovnaya branch, depth of -1920 meters

During the exploration of tributary in 2007 (UkrSA expedition) cavers reached the siphon. Yuri Yevdokimov was the one to dive into it. Parameters of the siphon are 17/-10. Siphon ends with gravel blockage.

The world's deepest Krubera Voronya Cave. La Siphon

YURIY KASYAN. Osnovnaya branch. Depth -1920 meters. La Siphon.

The world's deepest Krubera Voronya Cave. La Siphon

YURIY KASYAN. Osnovnaya branch. Depth -1920 meters. La Siphon.

S12. Yama (Pit) Siphon. The Osnovnaya branch, depth of -1785 meters

This siphon is located behind the Goluboe Ozero siphon. It was discovered by Oleg Klimchuk (Cavex expedition). The siphon was passed for the first time in 2007 by Gennady Samokhin (UkrSA expedition). Parameters of the siphon are 15/-1. The siphon is equipped with a fixed 10mm lifeline and can be passed without fins. The siphon has unpleasant turn and underwater well with depth of about 2 meters, for which the siphon got its name.

S13. Troinoi (Triple) Siphon. The Osnovnaya branch, depth of -1785 meters

This siphon is located behind the Yama siphon. The siphon was scouted by Gennady Samokhin and Yuri Evdokimov (UkrSA expedition, 2007). Siphon ended with two continuations. First passage after 25 meters of length and at a depth of 1.3 meters, led to upward branch with length of 50 meters. It ended by narrowing and sinter speleothems. Attempts to further break up the grate and pass on were not successful. The second course of 40 meters length and depth of 5.5 meters led to scouted earlier gallery, which ended with yet another siphon. Gallery was named Yantarnaya (Amber) due to the abundance of amber blurred speleothems. Siphon was called Yantarnii (Amber) a well.

S14. Yantarnii (Amber) Siphon. The Osnovnaya branch, depth of -1820 meters

During 2007 expedition Gena Samohin makes two dives into the siphon. During the second dive Gena manages to pass the bend at the depth of 20 meters and 130 meters length. However, because of the problems with the underwater equipment, further passage had to be stopped. Siphon was completely passed only in 2014, by Gena Samokhin. Back in 2007 he didn’t pass only 10 meters to reach the exit of the siphon. Unfortunately, disappointment was awaiting the diver. He emerged in the known part of the cave, near the Bolshaya Razvilka. Interestingly, that in 2005 (UkrSA expedition) Kolya Solovyev plunged into the opposite side of the siphon. In 2005 only limited amount of air was taken to the expedition. It was used to first pass Kvitochka and Maluk siphons. So Kolya dived into the Amber siphon with the remnants of the air and passed only 10 meters of it.

The world's deepest Krubera Voronya Cave. Yantarnii Siphon

KONSTANTIN STOILOV. Osnovnaya branch. Depth -1820meters. Yantarnii Siphon.

S15. Siphon at the mark of -1384 meters. Nekuybyshevskaya branch

Siphon blocked the way for UrkSA expedition cavers in 2008.

The world's deepest Krubera Voronya Cave. Siphon at the mark of -1384 meters

LEONID FEIGIN. Nekuybyshevskaya branch. Siphon at the mark of -1384 meters.

The world's deepest Krubera Voronya Cave. Siphon at the mark of -1384 meters

YURIY KASYAN. Nekuybyshevskaya branch. Siphon at the mark of -1384 meters.

In August 2009 there was an attempt to pass the siphon. Gennady Samokhin made several tries, but the siphon was too narrow for passing. On the same day Yuri Kasian found the bypass of the siphon. Traverse of the well above the siphon, and the narrow gap was found with the sound of falling water.

S16. Koluchka (Thorn) Siphon. Nekuybyshevskaya branch, depth of -1558 meters

Meeting with this siphon ended UkrSA expedition in 2009. In August 2010, Gennady Samokhin passed the siphon. Siphon is short, about 3 meters, but with a very complex configuration, with turns and narrowness, for which it received its name. The cave continues after the siphon. The first attempts of engineering works in the siphon ended up with caver poisoning from exhaust of gasoline perforator. In 2011 (UkrSA expedition) the level of the siphon was lowered with the use of flexible hoses and engineering work continued. For precaution a cylinder with compressed air was used. As a result of engineering work, the siphon has been formatted so it can be passage without diving.

The world's deepest Krubera Voronya Cave. Koluchka Siphon

YURIY KASYAN. Nekuybyshevskaya branch. Depth -1558 meters. Koluchka Siphon.

The world's deepest Krubera Voronya Cave. Koluchka Siphon

IEVGENIY LATA. Nekuybyshevskaya branch. Depth -1558 meters. Koluchka Siphon.

The world's deepest Krubera Voronya Cave. Koluchka Siphon

IEVGENIY LATA. Nekuybyshevskaya branch. Depth -1558 meters. Koluchka Siphon.

S17. Tunnel Siphon. Nekuybyshevskaya Branch, depth of -1697 meters

This is the last and still has not passed siphon in the Nekuybyshevskaya branch. During the expedition of 2010, an attempt was made to dive into the siphon, but the diver Gena Samohin could not find a passage in the stone blockage. Further work will be carried out to expand the channel-flows that bypass the siphon. Since there is no air draft coming from the channels, there is an assumption that after Tunnel siphon, there is another siphon awaiting cavers.

The world's deepest Krubera Voronya Cave. Tunnel Siphon

ALEKSANDR AKULENKO. Nekuybyshevskaya branch. Tunnel Siphon.
Yuriy Kasyan
Translation: Oleksandra Shturma

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