A protestor against a planned speed limit on Windermere in the Lake District has been fined for speeding on nearby Coniston Water.
The speed limit comes into force in March 2005
A 10mph limit for boats is already in force on Coniston, with a similar limit due for Windermere in 2005.
Thomas Marr from County Durham, who opposes the move, was filmed by rangers exceeding the limit.
Marr was fined £300 in his absence by Kendal magistrates on Monday when he failed to answer a summons.
Magistrates were told Marr was filmed by a Lake District National Park ranger as he drove a speedboat faster than the 10mph speed limit on Coniston.
The court heard that when he was approached by park staff, he told them he was doing it as a protest.
The court was told nothing had been heard from him since the event and in his absence magistrates found the case proved.
The case against two other men charged with similar offences was adjourned for a trial date to be set.
New regulations which will mean a 10mph speed limit on Windermere are due to be introduced in March next year with the Lake District National Park Authority saying it will restore the lake's tranquillity.
A high-profile campaign against the proposal has been mounted by objectors, who claim the speed limit will hit tourism.