Work has begun to rescue the sunken narrowboat from the Kennet and Avon Canal near Devizes.
The boat, the Lady Victoria, sank while negotiating Lock 22 at Lower Foxhangers on Wednesday night.
Staff from the Canal and River Trust have started putting a dam in the lock and will then empty it of water.
Workers will then get on to the boat and pump out the water. They hope this will result in the boat floating back to the top and be able to manoeuvre it out of the lock.
If the pumping operation is unsuccessful the boat will be lifted out by crane.
The Caen Hill flight of locks, between 22 and 44, are closed to boat traffic.