Classic dilemma........

Perhaps a huge lens so that you can zoom right in on the subject on the water and therefore cut out the black glare from the sun over the horizon?
Or did you try changing the angle of shot so you are looking down from height or walk up the beach to take the shot so that your camera lens isn't facing straight into the sun?(need a massive lens for that to compensate for moving further up the beach for that I think). I do this for landscape to help with the glare but don't know if it will work for surf shots.
Im not sure if there is a solution??? Need a photography expert to help with this one.