Adrian, I dont shoot surf (yet...) but the camera harness I made for snorkle snapping may work for you.
From a dive shop I purchased a length of 25mm webbing, a 25mm D ring and plastic slide and two 25mm fastex clips. I arranged the webbing to pass around my chest, cross over my back and over each shoulder in a continuous loop. The two fastex snaps act as 'breaks' for ease of donning and adjustment. The D ring and slide act as the attachment point for the camera which I secure close to me with either a double bolt snap or a cord leash.
Thanks Tim, looks like a spot of DIY is called for! Perhaps there's a gap in the market, when I did a google search it turned up some guys patent for a surf photographers harness, but no one seems to have made it yet. I'd get yourself down to the local patent office. ;-)