Last year there were just three possible sightings, but two were nothing more than waves or the wake from a boat.
The third was a duck, said Gary Campbell, president of the Official Loch Ness Monster Fan Club.
The lack of possible appearances prompted William Hill to hold over its Best Nessie Sighting of The Year competition, which carries a prize of £1000. There will be £2000 for the best sightings this year.
Mr Campbell has checked past records and confirmed 2013 was the first year since 1925 that there had not been a registered sighting.
He said: "In years gone by people rarely carried a camera and, when they did, by the time they were ready for taking a photograph whatever it was had gone.
"We would take people at their word. Nowadays everyone carries a phone camera and can take a picture of what they see.."
However, Mr Campbell insists that, given the number of unexplained sightings over the years, there is something in the loch. He said: "Unfortunately, the only way of proving it is to have a body and no-one wants a monster washed up on the beach."
Since 1996 the Official Loch Ness Monster Fan Club has recorded 89 "good" sightings.
But Mr Campbell said: "Over the last six or seven years, there have been very few sightings and, some years, there has only been one."
Last October skipper George Edwards, 61, admitted the picture billed as "the best ever taken of the Loch Ness monster" was fake.
He said the picture, published in August 2012, was "a bit of fun".
Mr Edwards, a cruise boat operator on Loch Ness, produced arguably one of the most convincing Nessie frauds since the "Surgeon's Photograph" taken by Dr Robert Kenneth Wilson and published in 1934.
It supposedly showed the monster's head and neck, but was proved to be a hoax.
Mr Campbell, who has compiled the list of sightings since 1996, said some could not be explained.
He claimed one of the closest encounters with Nessie was that reported by Robert Badger, a Paisley factory worker, who claimed to have touched her while swimming in Loch Ness. His story earned him £500 from William Hill for the best recorded sighting of 1998.
In 2002, the prize went to Glasgow postman Bobbie Pollock, who captured footage of something in the water while walking in the hills above Invermoriston Bay.