A boat sank into the canal after being deliberately set alight.
A passer-by raised the alarm after seeing the boat in flames on the waterway near Rose Bridge Academy in Ince.
Firefighters from Wigan and Hindley attended and pumped water out of the canal to tackle the blaze.
But the boat was completely destroyed and sank.
Police are reported to have had issues recently with youths getting on the boat and the cause of the fire is thought to be suspicious.