• The mysterious device was netted earlier this year by fishermen in the Adriatic.
• The U.S. Navy stepped up and claimed the device, though it didn’t explain what it was.
• The object was likely EARS, an underwater recording device designed to collect noises from the ocean floor.
A strange device hauled up from the depths of the Adriatic Sea is almost certainly an underwater recording system left behind by the U.S. Navy. The device, netted by Croatian fishermen, is identical to the Navy’s EARS sensor system. EARS is meant to record local undersea noises, revealing what sounds are normal in that part of the world’s oceans so a naval force can home in on noises that aren’t.
The device was caught on January 6, 2020, by the fishing boat Marian II. The boat was trawling in 460 feet of water when it snagged the 220 pound device. Fishermen brought it onto the boat and apparently had no idea what it was. Pictures of the device went up on social media and soon its owners, the U.S. Navy, called the trawler’s owners asking for the device back. The Navy paid for damage to the boat’s nets and the device was handed over to the U.S. Navy oceanographic survey ship USNS Bruce C. Heezen.
EARS, Sutton explains, stands for Environmental Acoustic Recording System. The acronym is exactly what it sounds like, an audio recording device that sits on the bottom of the ocean and records ambient sound. Sutton states that the device can record for up to a year at depths of more than 3,000 feet.
Why would the Navy want such a device? If the Navy knows what the Adriatic sounds like, that would enable it to more quickly identify unusual sounds—sounds that could indicate enemy activity, particularly submarines. The Navy could also work to make its own submarines blend in with typical area noise.
The device was apparently dropped in the Adriatic for retrieval in the future. EARS is designed to sit tethered on the ocean floor but separate from its anchor after receiving a coded signal from the Navy. Then the sensor package floats to the surface for retrieval by a passing ship. Clever, but not clever enough to thwart Croatian fishermen./ Popular Mechanics