The incident

An inland waterways motor cruiser was moored alongside a jetty when a local boat owner became suspicious of the lack of activity on board. He moored his boat alongside the jetty and went to investigate. He shouted to attract attention, but there was no response.


He proceeded to one of the motor cruiser’s windows and saw a person lying motionless on the forepeak bed. He called to a passing barge for help and the owner moored nearby. The two men then entered the aft canopied area of the motor cruiser.

They then saw a woman and a dog on the forepeak bed and a man slumped in the foot well at the bottom of the steps leading from the cabin to the helm area. All three appeared to be lifeless. One of the men then called the emergency services using his mobile phone.

The emergency services arrived about 30 minutes later. The rear canopy was unfastened and a firefighter tested the atmosphere. Ambulance personnel then examined the two occupants and confirmed that they were dead.

Probable cause

The post-mortem examination showed that the owner and his partner had died of carbon monoxide poisoning.

Lessons learned

  • The motor cruiser’s owner was probably charging the boat’s batteries by running the engine while alongside. Carbon monoxide from the wet exhaust then entered the accommodation through gaps in and around the canopy.
  • Exhaust fumes can enter a boat at any time depending on wind direction and airflows. Ensure that the accommodation area is well ventilated when the engine is running.
  • Ensure that a carbon monoxide alarm is fitted to the accommodation area of the boat. Check the alarm is working and test it according to the manufacturer’s guidance.