The eight-metre vessel, Ocean Blue, was extensively damaged after bursting into flames just outside the Harbour. Its two crew members were able to escape unharmed onto another boat.
The Fire and Rescue Service’s inshore lifeboat and RNLI St Helier all-weather lifeboat were both deployed to the incident in the Small Roads – just east of Elizabeth Castle – at around 4.23 pm on Thursday.
In a statement, a spokesman for the RNLI said that crews were initially unable to get close to the affected vessel because of explosions and due to flares, gas cylinders and fuel being stored onboard.
However, firefighters on the Fire and Rescue Service’s inshore vessel were able to use a portable firefighting pump to dampen down the burning boat before towing it into deeper water.
The larger RNLI all-weather lifeboat was then able to fully extinguish the flames using its onboard hydrant. It was later towed back to the Harbour.
The Coastguard said that the incident is now being investigated by the Fire and Rescue Service.