TRITON-AST

On the 22nd of August 2002. members of the Triton diving team Mirko Bevenja and Vladimir Taleski set a new freshwater Balkan record in deep air diving reaching a depth of 127 m.
The record was set at the Ohrid lake in Macedonia.

During this dive they used "Aladin" computers as gauges and Poseidon regulators. The dive was planed on specially modified software.

The Ohrid lake lie 700 m above the sea level, and the water temperature was as low as 6 degree C reaching a visibility between 5 and 10 m. According to tables the correction factor for this altitude is 1.08 which means that the equivalent depth (for decompression) at a sea level would be 137 m. The absence of a usable decompression chamber was also a big problem. The nearest was in Bujanovac (Yugoslavia), and the transport to this chamber (via helicopter) would mean flaying over a big mountain massive (not good from a DCS point of view).

It is usual to have a safety team, which means having divers on trimix posted every 50 m as a backup and a medical team with a chamber near and the staff alerted. At this dive 6 club members were present and the SSI diving instructor Milutin Sekuloski from Macedonia.

Profile and report (to enlarge click on the picture)

Some history facts

This unofficial discipline vas established after the World War II. The divers vent deeper and deeper. :

year depth place
1947. - 93m - Red Sea Frederic Dumas
1961. - 106m - Florida Jean Clarke Samazan
1963. - 108m - Florida Hal Watts
1965. - 109m - Florida Tom Mount & Frank Martz
1967. - 118m - Florida Hal Watts & A.J. Muns
1968. - 132m - Bahami Neil Watson & John Gruener
1990. - 137m - Roatan Bret Gilliam
1993. - 144m - San Salvador Bret Gilliam
1994. - 148m - Nassau Dan Manion
1999. - 156m - Mark Andrews

From the list above you can see that the record from 1968 lasted for 22 years. Many attempts to break this record finished tragically. Like in the world in our country this attempt also has his tragic actors.

Risk and consequences

*We do not suggest anybody who is not physically and mentally fit and is not aware of the possible consequences to try to execute similar dives. Once more we point out that the maximum limit of recreational diving is 40 m. *

There is an open question if such dives make sense. Today to these depths we can dive on gas mixes that are (relatively) safe. On the other hand every man has a nature curiosity that motivates him to try things that nobody did. Everybody should decide for him self. At summer 1975 in a attempt to reach a depth of 120 m two legends of Yugoslav diving, instructors Zoran Fotic and Dusan Rakic lost their lives in the deep blue of the Adriatic sea near the island Susac. Their bodies were never find.

The question of "the calculated risk" is open .

The main problems with this kind of diving are Nitrogen narcosis and Oxygen toxicity.

First symptoms of the nitrogen narcosis we can feel at a depth as "shallow" as 30 m. This is the reason why recessional diving is limited to 40 m. Narcosis is usually characterized by symptoms similar to alcoholic intoxication, such as impairment of thought, judgment, and the ability to perform tasks that require mental or motor skills.
Through a training it is possible to build a resistance to narcosis to some degree, but nobody can adopt to depths greater than 90 m. On the other hand such an adaptation requires an extreme training. For example Bret Giliam in 11 months before his world record attempt made 600 dives from which 103 were deeper than 90 m. He also made simulated dives in a chamber to a depth of 120 m .

The second problem (the silent killer) is Oxygen toxicity. It happen when the partial pressure of oxygen reaches over 1.6bar for some time, which on air would be a depth of 66 m.
The toxicity depends on the depth and on the exposure. The Oxygen hit ca come suddenly with weary little symptoms. The outcoming in many cases is death by drowning.

There are two different kinds of oxygen poisoning:

- Central Nervous system poisoning - Paul Bert effect;

- Pulmonary oxygen poisoning, Lorain - Smit effect;

Central Nervous system poisoning is more common among divers using the Close Circuit Rebreathers with oxygen (the Navy) at depths greater than 7 m. The causes and mechanism of poisoning are not 100% known.
Stimulating factors for CNS are:

- heavy work
- cold
- CO2 build up

The symptoms are:

- muscular twitching in the face, lips or hands
- white skin
- sweating
- confusion
- fatigue
- lack of coordination

Pulmonary oxygen poisoning is typical for long exposures to partial pressures of oxygen higher than 0.5 bar. The diver has symptoms similar to pneumonia, only that the diver does not respond to medical treatment. If a diver during the dive have any of the listed symptoms, has to quickly decent to a shallower depth.

The symptoms if any are progressing very quickly so you have to react immediately. The Oxygen poisoning is weary rear and happens only in deep diving at long oxygen decompression or in diving with the wrong gas at a wrong depth (mostly nitrox).

Our diver had undertaken serious physical preparations, made many build up dives and simulated dives in a hyperbolic chamber on ppO2 on 2.8bar (equivalent depth of 123 m.)