Francois Haussauer, 52, of Buckinghamshire, hired out his boat to tourists for voyages from France.

The Maritime and Coastguard Agency (MCA), which brought the prosecution, said Haussauers' yacht had failed to comply with safety regulations.

Haussauer was found guilty at Horseferry Road Magistrates Court of not having the appropriate documents.

'Passengers were friends'

The MCA said it had concerns about the vessel's steering, how the gas supply was routed and the location of the life-raft.

The MCA said the court was told Haussauer had failed to comply with the regulations despite attempts by the organisation to inform him.

In his defence the court was told the passengers were Haussauers' friends and not fee-paying holidaymakers, an MCA spokesman said.

Haussauer was found guilty of two counts of not having the appropriate Certification of Competence to take charge of the yacht, two counts of not having Load Line Certification for the vessel and of breaching a prohibition notice.

He was also ordered to pay the MCA's costs which have yet to be decided.