Mr. Campbell reported seeing a whale-like creature and the Loch's water "cascading and churning".
In 1934 a highly respected surgeon claimed to have taken a piture of the Loch Ness monster while driving along the Northern shore of Loch Ness.
On May 2, 1933 a local couple claimed to have seen "an enormous animal rolling and plunging on the surface".
Scholars of the Loch Ness Monster find a dozen references to “Nessie” in Scottish history, dating back to around 500 A.D., when local Picts carved a strange aquatic creature into standing stones near Loch Ness.
During the 1960s several British universities used sonar to explore Loch Ness. They didn't a lot, but on each exploration they detected large moving objects that they couldn't explain.
In 1975, Boston's Academy of Applied Science did an exploration combining sonar and underwater photography and discovered the giant flipper of a plesiosaur-like creature.