The closure of the Kennet and Avon Canal due to the capsizing of a narrowboat near Bath is likely to have a knock-on effect on boaters throughout Wiltshire.
The canal may have to be closed for a week after a boat became caught on the sill of Abbey View Lock, Bath, at about 2pm on Saturday.
It is thought a Welsh stag party had hired the boat and one person is thought to have to leaped to safety.
A spokesman for the Canal and River Trust said that the boat got stuck as the water drained out and rolled over and sank when the water rushed back in.
A crane will be needed to lift the waterlogged vessel out of the canal.
The situation has been complicated by the fact that the lock will have to be drained, which means that the fish in the lock will have to be taken out and released elsewhere on the canal.
Dale Marshall, the maintenance manager for the canal in the Bath area, said: “It is quite a big job to get it back afloat again and reopen the canal.
"People might think we just need to lift it back up and right it again, but the ballast in there will have shifted, the vents for the engines are below the water line, there’s all sorts of things which will mean we can’t just do that.
“So we will have to drain the water around it – and that means for about 250 metres of the canal as well – and take the weight with one or two cranes as the water drops.
"Dropping the water will mean we’ll have to undertake a fish rescue too before and as that happens, and so we have to arrange that to happen too.”
Although the canal is only closed between locks seven to 13, boats wishing to travel from Great Bedwyn, through Pewsey and Devizes to Bradford on Avon and Bath could welll be held up.