Boats and helicopters have joined the search for the chief executive of sportswear maker Quiksilver, after his empty boat was found washed ashore in south-west France. The port authority of the Atlantic beach town of Capbreton said the search was launched after Pierre Agnes' empty boat was found washed up Tuesday in nearby Hossegor. Maritime authorities said two boats and three helicopters are involved in the search. The area is known for intense, sometimes dangerous waves that are prized by surfers.