Ukraine has used naval drones to target Russian warships, tankers and naval bases since Moscow’s full-scale invasion began in 2022, but much of this activity has been constrained to the Black Sea, which the two nations border.
Ukraine’s military has so far not commented. Both Greek and Ukrainian media have identified it as likely a Ukrainian-made Magura drone.
Two reputable Greek news outlets are reporting that notes handwritten in Ukrainian were found aboard the vessel.
It was estimated to be carrying around 100kg (220lb) of explosives, prompting Greek authorities to conduct a controlled explosion in the sea near Astakos.
Specialist teams in the Greek armed forces are now inspecting the drone for clues as to its origin and purpose.
Greek newspaper Ta Nea reports that theories being considered are that the drone – with an estimated range of 432 miles (700km) – fell into the sea while being transported or was intended to target Russian shipping in the Mediterranean but lost contact with its operator.
The vessel had a built-in GPS that could have been affected by bad weather and sensors that were broken when it was discovered, according to public broadcaster ERT.
But the drone’s presence has prompted criticism that Greece’s Navy was ill-prepared for a new era of warfare.
“Unfortunately, all Greek women and men are realising that the country is an open vineyard,” opposition defence spokesman Michalis Katrinis commented.
Meanwhile, Greece’s Communist party said in a statement: “What business did the Ukrainian naval drone have in Greek territorial waters? What was its goal? Did the Greek government know if and in which operational plan it was part of? […] Are other similar drones of other ‘allies’ also operating in Greek territorial waters?”
The nationalist pro-Russian Hellenic Solution party called it a “conscious military provocation”.
Defence Minister Nikos Dendias sought to downplay the significance of the drone’s discovery on Saturday, saying: “Because we know what it is and what it contains, we have nothing to envy.”
He said that the Greek government was implementing policies that meant “our homeland can produce and be able to equip the Navy with the most advanced drones and anti-drone systems that currently exist”.
The discovery has put Greece’s national security agency, armed forces and several ministries on red alert.