A dive-team from Neptune’s Army of Rubbish Cleaners (NARC) carrying out a routine underwater clean-up off the west Wales coast have found what is believed to be a Russian sonobuoy, or hydroacoustic submarine-monitoring device.
Their discovery was made just days before the news that the Russian spy ship Yantar had been caught conducting operations on the edge of the UK’s 12-mile limit and responded by aiming lasers at the pilots of RAF patrol aircraft.
NARC is a group of volunteer divers who since 2005 have dedicated themselves to cleaning up underwater litter from ghost-fishing gear to shopping trolleys along the Pembrokeshire coast.
The sonobuoy was found on the first day of the group’s last weekend of the season, which also resulted in retrieval of some 250 angling weights and monofilament line.
A BBC team had covered NARC’s operations in the Skomer Marine Conservation Zone in October, and has now followed up on diver Tim Smith-Gosling finding the surveillance device wedged in a gulley off Wooltack Point, Jack Sound on Saturday, 15 November.
The divers later consulted port authority officials and the Coastguard about their “battered” find, which was 1.2m long and weighed about 15kg, and had compared it with similar objects found in Cornwall and Ireland in 2021, according to NARC chairman and founder David Kennard, who had been dive-marshalling at the time.
Sonobuoys have both a radio transmitter for use while afloat and hydrophone sensors for use under water, and are designed for anti-submarine warfare and acoustic research.
An unnamed independent defence analyst and submarine expert told the BBC that he was confident that the device was an imploded Russian RGB-1A device, typically deployed by Tupolev Tu-142M long-range maritime patrol aircraft.
The relative lack of marine growth on this and the similar devices found on UK, Irish and, in 2024, a Lithuanian beach suggested that all had been deployed in relatively recent years.
Another defence expert, Dr Andy Scollick, also identified the device as an RGB hydroacoustic buoy. He said it was similar to previously identified examples with its three vertically aligned hydrophones, but missing the sleeve that would have contained its serial number.
First used during WW2, sonobuoys are routinely deployed during naval exercises and operations. The Royal Navy did not comment directly on the discovery when approached by the BBC.
Divers are warned not to touch or move suspected sonobuoys because they can contain hazardous materials, but to report such finds to the Coastguard.
