A Thames mystery is deepening after a small, unlit vessel was filmed racing along the river under cover of darkness — with an RAF helicopter sweeping over the same stretch of water just minutes later.
The sighting unfolded just after 9.15pm on Tuesday, 6 October. Emanuele Biasiol, 31, had stepped onto the balcony of his Isle of Dogs home when he noticed a craft tearing past far faster than the usual traffic on the River Thames, heading southbound towards Greenwich.
Mr Biasiol said he was used to seeing military exercise boats and police launches moving at speed on this stretch of the river, so he glanced up expecting a familiar sight — only to realise the vessel was running with no lights at all.
At first he assumed it was a private boat being driven recklessly. But as it swept past, he realised the craft was too small to be an ordinary boat, appeared to have nobody on board and was showing no lights — so he pulled out his phone and started filming.
He described the vessel as eerily quiet, with no engine noise audible above the sound of the water it was cutting through.
Helicopter overhead minutes later
Mr Biasiol reported the encounter to police and was advised to log it online as suspicious activity. Within minutes of the sighting, the thump of a military helicopter could be heard overhead.
Data from the aircraft-tracking website ADS-B Exchange shows an RAF Chinook crossed the area roughly five minutes after the vessel was spotted. No official link between the helicopter and the mystery craft has been established.
What was the vessel?
After footage of the incident was shared online, some viewers suggested the craft bore a resemblance to the Kraken K3 Scout — a 2.5-tonne unmanned surface vessel of the kind used for autonomous trials and survey work.
Unmanned surface vessels, often called USVs or drone boats, are an increasingly common sight on British waters. Ranging from small survey craft to larger defence platforms, they can be operated remotely or sail pre-programmed routes with minimal human input, and are used for tasks including hydrographic survey, mine countermeasures research and equipment trials. The Thames — with its fast tides, restricted bends and constant commercial traffic — is a demanding environment in which to test them. Whatever the craft was, convention says it should still have been lit: even autonomous vessels are expected to comply with collision regulations when operating at night.
The Ministry of Defence, the Metropolitan Police, Saab and Kraken have been contacted for comment.
The rules of the river
Under the international regulations for preventing collisions at sea — enforced on the Thames by the Port of London Authority — any vessel under way at night must display navigation lights so other river users can see it and judge its course. An unlit craft moving at speed would present a serious hazard on one of the country’s busiest commercial waterways, which is shared by passenger Clippers, working barges and leisure boats.
Anyone who sees dangerous or suspicious activity on the river is urged to report it. The Metropolitan Police’s Marine Policing Unit patrols the Thames around the clock, and incidents can also be flagged to the Port of London Authority.
Heading for Greenwich
The vessel was last seen making for Greenwich — a borough whose naval heritage still runs through its streets. Whatever the craft was, and whoever was behind it, the questions are mounting, and with no official explanation yet offered, those who live and work beside the river will be watching the water closely.
