Expert Reveals Navigational Anomalies of KM Virgo 8 Before Capsizing in the Java Sea
A marine environment expert from the Institut Teknologi Sepuluh Nopember (ITS) has refuted claims of extreme weather during the capsizing of KM Virgo Transport 8 in the Java Sea on Sunday (13/9) early in the morning. Hydrometeorological data and navigation tracks instead reveal technical anomalies occurring moments before the ship lost contact.
ITS Coastal Engineering expert, Dr Eng Kriyo Sambodho, stated that the weather conditions in the Java Sea on the night of the incident did not fall into the extreme category, as also explained by the Meteorology, Climatology, and Geophysics Agency (BMKG). He noted that, according to his monitoring, wave heights in the Java Sea during the incident were recorded only in the range of 1.6 to 2 metres, with wind speeds of 20 knots and maximum gusts of 30 knots.
“The hydrometeorological conditions at the time of the incident do not show extreme levels according to BMKG classifications,” said the academic, commonly known as Dhodot, when met at ITS Surabaya on Tuesday (15/9).
Dhodot noted that while the weather might not be classified as extreme, it could still serve as a triggering factor, showing signs of adverse marine conditions. “However, it showed adverse marine conditions, such as southeasterly winds of around 20 knots, with gusts up to 30 knots and wave heights of 1.9–2.0 m. The orientation of the ship relative to these environmental conditions had the potential to reduce vessel stability,” he said.
Dhodot explained that with wave heights of 2 metres, seawater could very likely enter the ship’s deck through the ramp door if the vessel was not tightly sealed or watertight. This situation could trigger a chain reaction leading to a loss of balance and the tilting of the hull.
“It is still possible that the ship was already tilting from the start. Whether due to cargo shifting, water ingress reducing stability, engine failure, or a combination of all these factors,” he added.
Furthermore, Dhodot analysed the movement data of KM Virgo 8 through the records of the ITS Automatic Identification System (AISITS). This navigation data analysis successfully mapped anomalies just before the vessel, carrying 243 people, capsized in the Java Sea waters.
AISITS data initially recorded the ship moving normally after departing the port towards the Banjarmasin shipping lane. However, a misunderstanding arose in the public sphere that the Masalembu waters were a ‘dead zone’ where signals mysteriously vanished. “Many believed the signal was intentionally lost in the Masalembu waters, but in reality, the AIS ITS range ended in that area because the range of the ship’s radio transmitter and responder was beyond reach (a blank spot),” he explained.
Nevertheless, before the signal range ended at 01:00 WIB, AISITS data and subsequent reports recorded a drastic change in the situation. Based on the collected data, an anomalous turning point was identified at the last coordinates when the captain reported the ship began tilting at 00:49 WIB. At that time, the ship’s speed was recorded to have dropped sharply to approximately 6 knots.
Not only did the vessel slow down, but movement data also showed that the ship’s heading had changed and deviated from its intended shipping route to Banjarmasin. “The ship shifted off course. Why was it not on its path? Was it because the engine had failed, making it unable to manoeuvre, or was it carried by the current?” Dhodot speculated regarding the anomaly.
KM Virgo Transport 8 was reported to have lost contact in the Java Sea waters on Sunday (13/9) at 02:00 WITA, while sailing from Surabaya to Banjarmasin since Saturday (12/9). KM Virgo was transporting 243 passengers and crew, as well as 89 vehicles.
Of the 243 victims, 108 have been evacuated safely and 6 fatalities have been confirmed, while 129 others remain missing and are still being searched for.