Safety advice has been issued to sailors after a catastrophic fire, which caused the sinking of a catamaran off the coast near Lowestoft.

The ECC Topaz was undergoing engine trials when a blaze broke out, forcing its three-man crew to abandon ship and take refuge on a life raft.

They were winched to safety by the Wattisham-based RAF helicopter shortly before the Spirit of Lowestoft lifeboat arrived.

The fire was discovered by the skipper after it spread to the wheelhouse. Efforts to extinguish it were made, but failed.

The 14m long ECC Topaz, a passenger transfer vessel used to ferry workers between windfarms and vessels and shore, which could carry 12 people, sank within 35 minutes.

A report into the incident, which happened off Lowestoft on January 14 last year, blamed an uninsulated section of exhaust pipe from a diesel-fired air heater for the blaze.

The investigation carried out by the Marine Accident Investigation Branch (MAIB) found the exhaust pipe had either made contact with the plywood under-deck, or exhaust gas from a degraded pipe came into contact with inflammable material stored in the heater compartment.

An oil-fired heater was not categorised as an item of machinery in the regulations to which ECC Topaz was constructed and so the compartment in which the heater was kept was not required to be fitted with fire detection or fire suppression equipment.

The maximum temperature rating of the exhaust pipes recommended by the heater manufacturer was 350C (662F), whereas the actual exhaust temperature measured at the heater outlet was around 440C (824F).

The MAIB said: 'The annual service of the air heater as per the heater manufacturer's Recommended Service Schedule was not carried out, thereby missing the opportunity to identify the deteriorating state of the air heater and its exhaust system.'

A safety bulletin highlighting the fire risk posed by uninsulated exhaust pipes and a safety flyer specifically aimed at the leisure boating sector have been published by the MAIB.

The branch's report said The British Marine Federation had made several amendments to the draft standard for heating appliances based on the lessons learnt from the accident, and the Maritime and Coastguard Agency had modified its draft revision to the code of practice for safety of small workboats and pilot boats.