From the Yorkshire Post News:
Gordon Holmes, from Shipley, travelled to the Scottish Highlands to use new hydrophone equipment in an attempt to eavesdrop on Nessie in the water. "I saw something moving on the surface of the water so I dashed to get the camera. It wasn't a wave because it was going in the opposite direction to the waves that I could see and the top half of it seemed to be black... At its closest point it was about 100 yards away from me. It seemed to be travelling faster than a human could walk."
Of course it could also be an otter or a large fish.