Jersey's emergency services and about 100 actors took part in the third day of Operation Resilient Islands – a simulated exercise in which a ferry named Jaguar suffers steering problems and crashes into a cruise ship carrying 4,000 passengers.
The programme began on Monday and on Tuesday a French search and rescue helicopter airlifted firefighters onto the Duke of Normandy tug, which was being used as the Jaguar.
Yesterday, Condor Rapide was drafted in as the Jaguar to give the emergency services the chance to practise the drill on a ferry.
In the scenario, Jaguar had been towed into Jersey's harbour while a fire spread through its car deck.
During yesterday's operation, firefighters had to gain access to the vessel while a machine pumped smoke onto the deck to simulate a real blaze.
Mark James, Jersey's chief fire and emergency planning officer, said the operation had gone as he had hoped and that the drill had highlighted the importance of communication between the emergency services as well as organisations such as Ports of Jersey and St John Ambulance.
He added: 'An incident of this scale would hopefully never happen, but the only way to be prepared is to do exercises such as this.'
