Searches
Loch Ness Phenomena Investigation Bureau (1962–1972)
The Loch Ness Phenomena Investigation Bureau (LNPIB) was a UK-based society formed in 1962 "to study Loch Ness to identify the creature known as the Loch Ness Monster or determine the causes of reports of it." The society's name was later shortened to the Loch Ness Investigation Bureau (LNIB), and it disbanded in 1972. Its main activity was encouraging groups of self-funded volunteers to watch the loch from vantage points with film cameras with telescopic lenses.
Robert Rines studies (1972)
In 1972, a group of researchers from the Academy of Applied Science led by Robert H. Rines conducted a search for the monster involving sonar examination of the loch depths for unusual activity. A submersible camera with a floodlight was deployed to record images below the surface. If Rines detected anything on the sonar, he turned the light on and took pictures.
Operation Deepscan (1987)
Operation Deepscan was conducted in 1987. Twenty-four boats equipped with echosounder equipment were deployed across the width of the loch, and simultaneously sent acoustic waves. According to BBC News the scientists had made sonar contact with an unidentified object of unusual size. Sonar expert Darrell Lowrance, donated a number of echosounder units used in the operation. After examining a sonar return indicating a large, moving object at a depth of 180 metres, Lowrance said: "There's something here that we don't understand, and there's something here that's larger than a fish, maybe some species that hasn't been detected before. I don't know."
Explanations
Elephant
In 2006, palaeontologist and artist Neil Clark suggested that travelling circuses might have allowed elephants to bathe in the loch; the trunk could be the perceived head and neck, with the head and back the perceived humps.
Trees
In 1933, the Daily Mirror published a picture with the caption: "This queerly-shaped tree-trunk, washed ashore at Foyers [on Loch Ness] may, it is thought, be responsible for the reported appearance of a 'Monster'". A decomposing log could not initially release gases caused by decay because of its high resin level. Gas pressure would eventually rupture a resin seal at one end of the log, propelling it through the water (sometimes to the surface). According to Burton, the shape of tree logs (with their branch stumps) closely resembles descriptions of the monster.
Seiches and wakes
Loch Ness, because of its long, straight shape, is subject to unusual ripples affecting its surface. A seiche is a large oscillation of a lake, caused by water reverting to its natural level after being blown to one end of the lake (resulting in a standing wave); the Loch Ness oscillation period is 31.5 minutes.
Folklore
In 1980 Swedish naturalist and author Bengt Sjögren wrote that present beliefs in lake monsters such as the Loch Ness Monster are associated with kelpie legends. According to Sjögren, accounts of loch monsters have changed over time; originally describing horse-like creatures, they were intended to keep children away from the loch. Sjögren wrote that the kelpie legends have developed into descriptions reflecting a modern awareness of plesiosaurs.
Plesiosaur
In 1933 it was suggested that the creature "bears a striking resemblance to the supposedly extinct plesiosaur", a long-necked aquatic reptile which became extinct during the Cretaceous–Paleogene extinction event.