Some info on the photos:
"Single page consisting of three photographs of Loch Ness monster water disturbance in the Scottish Lake credited to the Loch Ness Phenomena Investigation Bureau, Ltd. and released on Saturday, May 25, 1968. The following information accompanied the photograph:
"Caption with MONSTER
"Release Saturday, May 25. 1968
"WHY THE SEARCH GOES ON
"These pictures, taken last summer, are a major reason for expanding the Loch Ness monster hunt this year. A long-range movie camera mounted not he shore of the Scottish lake detected a wake-like disturbance moving across the surface of Loch Ness (top and middle pictures). When a power boat approached the area, the disturbance vanished, leaving only the ripples behind (bottom picture.)
"Picture credit: Loch Ness Phenomena Investigation Bureau, Ltd.
"From World Book Science Service
From the estate of Roy Mackal."
Pretty cool stuff!