Two men who died in their bunks overnight on a scallop dredger were poisoned by carbon monoxide, initial findings of a accident report have indicated.
Resting at Whitby in Yorkshire from fishing, the 26-year-old skipper of the dredger Eshcol and his 21-year-old crewman had lit the grill of a butane gas cooker fitted in the wheelhouse in order to warm both the wheelhouse and the adjacent sleeping area.
The safety bulletin from the Marine Accident Investigation Branch (MAIB) went on: "When they were not seen as expected the following morning, crewmen from fishing vessels tied up close by forced open the wheelhouse door.
"The gas grill was still lit and the wheelhouse was full of fumes. The two men were dead in their bunks. Eshcol was not fitted with a carbon monoxide alarm."
The incident happened on January 15 2014. The skipper was father-of-two Mark Arries and the crewman was Edward Ide, who had a four-month-old son. Both men were from Northumberland.
Saying that a full report would follow when its investigation was completed, the MAIB published safety guidance.
It said gas cookers were designed for cooking, not domestic heating and that cookers needed to be checked and maintained regularly.
The MAIB said carbon monoxide (CO) was a lethal gas that was difficult to detect and that crews needed to be vigilant to recognise the first signs of CO poisoning.
The bulletin went on: "Carbon monoxide alarms are not expensive and should be fitted."