Rob Jones, 35, from North Wales, shared the footage taken on Monday of a mysterious shape moving across the Loch.
A large group of tourists watched and took pictures as the object moved slowly close to a passing boat before disappearing.
Earlier this year Gary Campbell, keeper of the Official Loch Ness Monster Sightings Register, admitted that he was ‘worried’ by the lack of sightings, after eight months without a hit.
He said: “Last year was a record year with eight sightings but then she seems to have disappeared.”
essie usually appears in the summer, although it isn’t unheard of for her to be spotted during the winter months. Despite the high number of Nessie sightnigs in 2016 - the best year since 2000 - the last recorded sighting of Scotland’s most famous resident was on August 21 last year.