There`s been no shark attacks in North Sea ever and only confused reports of sightings of any sharks likely to pose any type of threat to humans whereas the red sea is full of all types of shark; combined with the fact local dive shops have been chumming water close to shore both attracting sharks closer to shore and familiarising them with humans. Shark attacks in red sea were inevitable but dont actually think windsurfers are in any particular real danger !! Think you are more likely to die of bee stings or on drive to coast than be attacked by sharks even in waters they inhabit. You are in far more danger in our north sea from pollution !!! Reckon its a fisherman`s tale; re sharks in North sea. (apart from Basking and occasional Porbeagle; neither of which pose any threat.)
Having said that we were sailing above sharks in waters between Feurteventura and Lanzarote and I was really intimidated !!!!