A Royal Navy attack drone crashed into a luxury racing yacht in Portsmouth Harbour, leaving behind damage worth thousands of pounds.
The 24-foot rigid inflatable drone, known as Rattler 4, collided with the 55ft yacht Lutine while it was sailing — despite the yacht having right of way.
A harbour source said the drone “went rogue” before the collision earlier this month.
The Lutine, valued at around £400,000, is owned by Lloyd’s of London.
Senior naval officers have launched an investigation into the crash, according to reports.
The yacht suffered a deep gouge to its stern and had to undergo repairs in dry dock after the impact.
Although both vessels were badly damaged, they remained seaworthy.
The satellite-controlled drones are designed to strike warships in coordinated “wolf pack” formations.
Seven Rattler drones have been carrying out military exercises in Portsmouth Harbour since March.
This is not the first incident involving the Rattler fleet.
Last year, both a tugboat and a Gosport Ferry had to take evasive action to avoid one of the drones.
The craft were meant to stay at least 650 feet away from other vessels.
The Fleet Experimentation Squadron, which tests advanced naval technology, reportedly built the drones in just a matter of weeks.
Portsmouth Harbour covers 55 square miles and is home to a major naval base, cross-channel ferries, cargo services, marinas, and routes to the Isle of Wight and Gosport.
The King’s Harbour Master Portsmouth had issued prior warnings to sailors about the drone trials.
The notice stated exercises would be suspended if a close-quarters situation developed.
It also said the unmanned surface vessels would be remotely controlled and operated under international collision-prevention rules.
Local sailors said drone testing has become increasingly common, though most drills usually take place outside marina boundaries.
One sailor told The Sun: “We’ve seen the Lutine plenty of times but had no idea what happened. We only noticed the damage.”
The Royal Navy said it is reviewing the incident.
A spokesperson said: “We are investigating an incident involving a Royal Navy Rattler craft and a civilian yacht during a controlled training exercise within Portsmouth Harbour.”
Guy Williams, commodore of Lloyd’s Yacht Club, added: “We can confirm the incident happened, but we have nothing further to say.”
