Thanks guys, I guess they are contrails from commercial jets, this is the second version of this shot the first was in colour and I didn't really like it. I would have got a much better shot had it not been for a young boy who was expressing his concern over the fact I might drop my camera in the water. Just as I turned to him to let him know all was fine a couple of ducks landed right in frame, so I missed that. On the up side I don't think he took to long to dry off!!