The Great Orm of Loch Ness : A Practical Inquiry into the Nature and Habits of Water-Monsters

Just below the surface, I then made out a shape. It was thick in the middle and tapered towards the extremities. It was a sort of blackish-grey in colour. To demonstrate that it was no trick of light-defraction, it moved steadily from one side of the leat to the other and then back again. When a chance puff of wind touched the surface it disappeared in a maze of ripples but when the water stilled it was always there. Its size—judging from the width of the leat—was between 40 and 45 feet long. No details were visible nor did any portion of it again break surface. It was simply an elongated shape of large size moving purposefully to and fro at the edge of deep water. —F. W. Holiday, The Great Orm of Loch Ness