The Guernsey court defused the situation further by effectively ruling that the infringement had been a relatively minor one, and fining him only pounds 1,250 for illegal fishing in British waters and a further pounds 2,500 for refusing to comply with orders from a Fishery Protection Officer.
Michel Mesnage, 40, had faced fines of up to pounds 50,000 and confiscation of his equipment for the first offence, and up to pounds 5,000 for the second.
The charges followed an incident on 28 March when La Calypso was seen by the minesweeper HMS Brocklesby just inside a six-mile limit to the west of Alderney.
Three Royal Navy officers on fishery protection duty who boarded La Calypso were kidnapped and taken to Cherbourg, despite ordering Mr Mesnage to sail to St Peter Port, Guernsey.
Fishermen in Normandy had threatened to renew a ban on British fish in French ports if the skipper was found guilty.
But on the second day of his trial, the captain of Cherbourg-based La Calypso changed his plea to guilty after studying the prosecution's positions and charts and taking the advice of a maritime expert at the French embassy in London.
John Greenfield, for the defence, said: 'We accept at certain times on the day in question part of Mr Mesnage's line was straddling the six- mile limit and the boat was within the six-mile limit. He has no alternative but to plead guilty.'
After the hearing Mr Greenfield, who described the outcome as 'fair and reasonable', said the money for the fine was being loaned to Mr Mesnage by a French resident of Guernsey.
Meanwhile, in London, the Ministry of Agriculture, Fisheries and Food rejected calls from fishermen on both sides of the Channel to solve the row over disputed waters with further talks. The ministry renewed its insistence that the treaty between Britain and France defining territorial waters around the Channel Islands was unambiguous, and would not be renegotiated.
'We have had no approach from the French government, and we see no need to renegotiate,' a spokesman said yesterday.
On Monday, after landing the first fish for more than a week at Cherbourg, fishermen from Guernsey, Alderney, Jersey and England signed an informal agreement with the local men calling on their respective governments to sort out the problems of disputed waters.