Croatian fisherman discovers suspicious orange cube that belongs to the US military

When a crew of Croatian fishermen netted a mysterious orange cube in the waters of the Adriatic, they had no idea that the device was connected with a puzzling US Navy operation in the area. Spoiler alert: it’s about Russia.

Trawling between the islands of Mljet and St. Andrew last week, the crew of the Marian II, a Croatian fishing boat, pulled something unusual out of their nets: an orange cube, weighing 100 kilos and measuring 130cm wide, with an anchor underneath.

Fisherman Darko Kunac Bigava took the cube ashore, and local media began to speculate as to what exactly it was. It didn’t take long for internet sleuths to link its appearance with the activity of a US Navy vessel in the area.

According to open-source mapping software, the USNS Bruce C. Heezen, a Pathfinder-class oceanographic survey ship, had been crisscrossing the same patch of water as the Marian II, evidently looking for its lost cargo.

Local news site Morski.hr wondered why exactly a US warship “did such maneuvers in our territorial waters, far away from Rijeka,” where it had been undergoing repairs. The Navy came knocking on Bigava’s door shortly afterwards, asking the Croatian fisherman to return the device.

Bigava said that the Americans escorted him to his ship, took the device, and handed him around $3,000 for his time and for his damaged fishing nets.

So what had Bigava stumbled upon? The first clue is in a label attached to the box. The sticker contained barcodes and tracking numbers, and indicated that the object was sent to Croatia by courier from the Stennis Space Center in Mississippi. Though this center is known for testing rocket engines, it is also home to several naval units, including the Naval Oceanographic Office, responsible for collecting and processing underwater samples and mapping data. 

The mystery was solved on Tuesday, when US Military Sealift Command spokesman Travis Weger told The Drive that “Bruce C. Heezen was executing an oceanographic survey, which was coordinated with Croatian authorities.”

Weger said that the cube is a kind of buoy with a transponder attached, used in the sonar scanning of the ocean floor. The Bruce C. Heezen had “deployed the float in Croatian territorial waters to test upgraded systems.”

Of course, the US is not simply mapping the seabed of the Adriatic for mapping’s sake. The US Navy claims to have noticed an increase in Russian submarine activity in the wider Mediterranean region, and has already reactivated the US 2nd Fleet – which includes a number of Virginia class submarines – in response. 

Though Weger declined to provide any further information, Forbes writer and maritime expert H.I. Sutton noted that a Teledyne Model R12K Acoustic Transponding Release and a Kongsberg cNode transponder were attached to the buoy. According to Teledyne, the R12K is used for “deep water asset recovery,” and upon receiving a command from the surface, jettisons a weight, allowing the buoy to be collected.

The US and Croatia worked together on the Bruce C. Heezen’s mapping mission, as is normal for NATO allies. However, other countries have taken a dim view of American oceanographic missions in the past. Chinese authorities seized an underwater drone belonging to the USNS Bowditch – a sister ship of the Bruce C. Heezen – in the South China Sea in 2016.

Washington maintained that the drone had been conducting mapping operations below the disputed waterway, and the Chinese military handed the vessel back over after a brief diplomatic spat.

Like this story? Share it with a friend!