I'm astounded that anyone would want to go over old ground but okay.
For years skeptics were sure that the photo was somehow a hoax. But no rigorous studies of the image were conducted until 1984 when Stewart Campbell analyzed the photo in a 1984 article in the British Journal of Photography. Campbell concluded that the object in the water could only have been two or three feet long, at most, and that it probably was an otter or a marine bird. He suggested it was likely that Wilson knew this to be the case.
But as it turned out, Campbell was wrong. The object in the water was not a form of marine life. It was a toy submarine outfitted with a sea-serpent head. This was revealed in 1994 when Christian Spurling, before his death at the age of 90, confessed to his involvement in a plot to create the famous Surgeon's Photo, a plot that involved both Marmaduke Wetherell and Colonel Wilson.
According to Spurling, he had been approached by Wetherell (his stepfather) who wanted him to make a convincing serpent model. Spurling did this, and this model was then photographed in Loch Ness. The picture was then given to Wilson, whose job it was to serve as a credible front-man for the hoax.
Apparently Wetherell's motive was revenge, since he was still smarting from his humiliation over the hippo-foot tracks. "We'll give them their monster," his son later remembered him saying.
In the original version of the image (bottom) the diminutive size of the Nessie model in relationship to the Loch can be seen. (The dark band along the top of the picture is the opposite side of the Loch.) The image given to the media was cropped to hide this perspective, making the "monster" appear larger than it actually was.
Martin, D. & Boyd, A. (1999). Nessie: The Surgeon's Photograph Exposed. Thorne Printing.
SOURCE
As far as I'm aware this is the accepted story behind the picture. I've never heard anyone try to dispute it, especially after investiagtors made their own Nessie model and came up with virtually the same picture.
I'm not out to knock you I just can't understand why you want to go over this again. However, if I did offend you please accept my apologise.
Mod Edit: Added External source tags.
[edit on 20-8-2009 by Gemwolf]
). Do these conclusively prove that the photos show an unknown animal? No, but they do point to the dubiousness of
Spurling's "deathbed confession". Also, why would no one else come forward and admit to the Hoax before their deaths, especially Wetherell
himself? Wouldnt taking the secret to his grave render the whole endeavor pointless? I find it hard to believe that he would depend on another
co-conspirator to reveal the secret long after his death. 
