The planned depth and dive time was going according to plan, until Andrey experienced a loss of consciousness on his ascent at around 15m. The safety team performed an underwater rescue and escorted him to the surface.<\/p>\n
Following a rescue breath, it appears that Andrey regained consciousness fairly quickly on the surface, and CMAS told us that three safety divers then began escorting him towards the medical boat.<\/p>\n
CMAS also said that: \u201cit\u2019s important to note that the safety divers were not wearing their official safety rash guards. This detail may have led some observers to mistake them for athletes\u201d.<\/p>\n
As Andrey appeared to have recovered already, giving an OK sign to the team, only one safety diver remained with him to finish escorting him to the medical boat, while the other two returned to the diving line. Unfortunately, Andrey then started to express alarming symptoms of DCI: Decompression Illness (a blanket term which covers any injury from gas bubbles caused by pressure changes) including paralysis of his right side. It is unclear whether this was specifically DCS: Decompression sickness (gas bubbles forming in the tissue), or [C]AGE: [Cerebral] Arterial Gas Embolism (gas bubbles that enter the arterial bloodstream [and make their way to the brain]), however treatment is the same for both. This also included his head dropping and his eyes rolling back.<\/p>\n
It appears that Andrey then lost consciousness again, and an athlete\/doctor on scene jumped from the athlete\u2019s boat to help get him onto the first aid platform. From here CMAS told us that \u201cdoctor intervention took place\u201d, that \u201call appropriate medical measures were applied, including oxygen administration\u201d.<\/p>\n
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Photo courtesy of CMAS<\/em><\/p>\n They continued to tell us: \u201cIt must be emphasised that two serious incidents occurred in immediate succession: in the case of Davide Carrera, a suspected DCS episode; and in the case of Andrey Matveenko, a deep blackout with pulmonary edema and suspected DCS. The doctors carried out a double evacuation in the shortest possible time, loading both athletes onto the boat. There was a delay of approximately two to three minutes in the evacuation protocol, but this did not affect the athletes\u2019 recovery outcomes\u201d.<\/p>\n CMAS said in their statement<\/u><\/a>: \u201cAndrey was transferred by ambulance to Lefkada public hospital, then to the emergency neurological clinic of Thriassio public hospital in Athens, before being admitted to the naval military hospital where he remains hospitalized and under treatment. He is currently receiving treatment in a hyperbaric chamber and is monitored by the neurological clinic\u201d.<\/p>\n There have been online claims that the competition doctor on the scene initially objected to Andrey\u2019s need for a chamber. Responding to this, CMAS have stated: \u201cDr. Chatzigeorgiou never expressed any objection to Mr. Matvenko\u2019s admission to the hyperbaric chamber, as this decision was not within his responsibility. This was also confirmed during the athletes\u2019 meeting (with around 40 athletes and coaches), when it was explained that certain comments made were unfounded and intended to cast doubt on the doctor\u2019s conduct\u201d.<\/p>\n Despite Andrey not being a DAN member, DAN was contacted regarding this case and offered free medical advice and guidance, both through the international medical hotline doctors and our Greek medical officer. DAN was not contacted about or involved in any other cases from the CMAS World Championship 2025.<\/strong><\/p>\n Photo courtesy of CMAS<\/em><\/p>\n It has been said that Andrey was not given any treatment within a hyperbaric chamber until the early hours of the following day, with a delay between the first and following treatments, too. The incident occurred around 11:20am on the 6th September, CMAS reports that the first treatment was at 02:30am on the 7th, and the second at 00:30 on the 8th, with more regular treatment ongoing from there.<\/p>\n But is this the fault of CMAS? The event organisers? Or is it Greek medical procedures regarding Taravana (DCI in freediving)? Well, this is what\u2019s up for discussion\u2026<\/p>\n There are arguments that the event organisers (Diving Greece Organising Committee) were not prepared enough for serious injuries occurring, including claims that more specialised equipment should have been onhand. Others have suggested more communication between the organisers and the nearest hyperbaric chamber may have sped up Andrey\u2019s treatment. However, the Diving Greece Organising Committee has denied this, telling us: \u201cLocal hospitals and the hyperbaric chamber in Athens were informed in advance about the start of the competition and were on alert that freediving athletes with possible related medical issues might need to be transported to them during the event. All of the above was of course done weeks before and was written\u201d, CMAS confirmed this saying: \u201cEmails from the organisers confirm these communications\u201d. They also had a detailed plan in place that would transfer a diver with DCI symptoms to a chamber within an estimated four hours, or quicker with a helicopter.<\/p>\n So if the chamber was aware of the competition happening and the potential injuries that could occur, why was it all so delayed?<\/p>\n It seems that although medical procedures in Greece work efficiently for scuba divers who experience DCI, there can be delays when it comes to freedivers with the same symptoms. Perhaps this is because they just don\u2019t see it as often, and as there are nowhere near as many documented cases. We spoke to Dr Evangelos Papoutsidakis who was the hyperbaric doctor advising on the situation over the phone via DAN, who told us that there was: \u201ctoo much of a delay\u201d, and that the problem is \u201cmany doctors don\u2019t understand freediving physiology\u201d. He concluded by saying that \u201cfreedivers need more protocols in place\u201d and if the World Championship is to happen again in Greece there needs to be \u201cmore communication with the naval hospital first\u201d.<\/p>\n Due to the lack of research and -outside of the freediving community- general knowledge surrounding Taravana-specific symptoms and treatment, it might be understandable that a medical doctor weighing up the situation, who has little personal knowledge of apnea, might hesitate to put a person into a hyperbaric chamber, if that person is displaying similar signs and symptoms similar to that of other non-diving related illnesses. Afterall, that doctor holds the responsibility if something goes wrong or the incorrect treatment is given. The fact is, the literature just isn\u2019t there yet to help aid that decision. However, there have been cases with much quicker hyperbaric treatment in other areas of the world. So, we are left with the question, is Greece the best option for future World Championships?<\/p>\n Concerned freedivers online have suggested that when athlete Davide Carrera experienced symptoms of DCI on the same day as Andrey\u2019s incident, and CMAS Chief Of Safety Roberto Butera did a couple of days later too, they both performed IWR: In Water Recompression (going to depth for an extended period of time to breathe oxygen and recompress following DCI symptoms). Some wondered why this wasn\u2019t offered to Andrey, too.<\/p>\n Athlete Talya Davidoff echoed this in her Instagram video explaining why she had dropped out from the competition, saying that both lines that had oxygen attached at 5m deep (a standard set up at competitions to allow for divers to breathe oxygen as a prophylactic to potentially reduce the likelihood of DCI symptoms after a deep dive) were occupied by other divers. She said: \u201cno oxygen available for Andrey\u201d. Andrey\u2019s coach Tatiana who was in the water with Andrey during the incident also reportedly asked for Andrey to be placed on the underwater O2 station, however, CMAS says Andrey was already unconscious again at this point.<\/p>\n Photo courtesy of CMAS<\/em><\/p>\n In response to all this CMAS told us: \u201cThe safety protocol prescribes that, in the event of a blackout or suspected squeeze, the athlete must be assessed by the medical staff before being authorized to start the deco-oxygen procedure. Because of this, it\u2019s impossible to know in advance when the lines will be available, not because blackout divers must first see a doctor, but because, under the current protocol, the deco-O\u2082 station isn\u2019t an emergency resource. It\u2019s meant as a preventive measure. Some athletes choose to relax for 20 minutes and swim around after their dives before using the deco-O\u2082 station, while some deep divers decide not to use it at all. For this reason, predicting its availability is not possible. However, in the case of Matvenko, he was not capable of performing the five-meter, five-minute protocol, nor of expressing the will to do so, due to his medical state at that time. And Andrey could not have been forced into a practice to which he had not previously agreed at the time of signing up for the competition. This procedure was never presented as an option when athletes registered, so we could not take responsibility for bringing someone underwater with oxygen against their will. This medical practice does not yet have sufficient scientific evidence, it is not officially approved, and it is not part of the protocol; therefore, we cannot assume responsibility for applying it. If Andre had been fit and had personally asked to go underwater to five meters to carry out the deco-oxygen procedure himself, we would have allowed it. However, such a request was never made by him, it came only from his coach, Tatiana, when Andre was already unconscious\u201d.<\/p>\n They added: \u201cMr. Butera consciously and independently decided to act outside the official competition protocol and assumed all related risks regarding his health and organisational responsibility. The same applied to Davide Carrera, who extended his decompression stop beyond the limits set by the protocol. These were personal decisions, not acts of favouritism, and Andrei Matvenko, in contrast, was not in a position to make such a decision and could not be compelled to follow a protocol outside the competition\u2019s official framework\u201d.<\/p>\n![\"\"](\"https:\/\/alertdiver.eu\/wp-content\/uploads\/2025\/09\/freediver3_1000.jpg\")
<\/p>\nA delay in treatment<\/h3>\n
In Water Recompression and its risks<\/h3>\n
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