Over the years and decades people have seen the Loch Ness Monsters, photographed the mysterious beasts, and took to the water on boats. There is, however, another angle to the mystery of the Nessies: it's that of sonar. I say this because Roland Watson - one of the key figures in the quest to solve the puzzle of the Nessies - has highlighted information on a new, sonar-based case. Roland has an excellent blog that reveals all of the new data - and new looks at old cases, too. With that said, let's see what we can learn about this new case. Over to Roland: "I note I had not posted on the Loch Ness Monster since October, having posted twice on her "sister" in Loch Morar. So, I wanted to remark on a sighting report made in the Summer at the loch. Gary Campbell, over at his Loch Ness sightings register website, had (last time I looked) registered a total of 13 sightings thus far for 2021. Helpfully, he has split them into two sections, those at the loch and those via the webcam run by Mikko Takala. The total was eight webcam and five at the loch. I have already made my views on the webcam reports known before and await better equipment for webcam enthusiasts to use. It is one of the in situ sightings I move onto. This was a sonar contact from one of the tourist cruise boats that ply their trade on the loch. The description from Gary's site is brief: '26 August - Benjamin Scanlon was on holiday with his family and took a trip on the 'Nessie Hunter' of Loch Ness Cruises. He spotted something on the sonar on the boat and caught the image below. Captain Mike of the boat estimated it to be 3-4 metres in length, at a depth of about 20 metres, while the boat was in water about 40 metres deep.'"
But, what, exactly, is sonar? How does it work? What are some of the other cases. We'll begin with the science of sonar. The United States Government's National Oceanic and Atmospheric Administration (NOAA) explains: "Sonar, short for Sound Navigation and Ranging, is helpful for exploring and mapping the ocean because sound waves travel farther in the water than do radar and light waves. NOAA scientists primarily use sonar to develop nautical charts, locate underwater hazards to navigation, search for and map objects on the seafloor such as shipwrecks, and map the seafloor itself. There are two types of sonar—active and passive. Active sonar transducers emit an acoustic signal or pulse of sound into the water. If an object is in the path of the sound pulse, the sound bounces off the object and returns an 'echo' to the sonar transducer. If the transducer is equipped with the ability to receive signals, it measures the strength of the signal. By determining the time between the emission of the sound pulse and its reception, the transducer can determine the range and orientation of the object. Passive sonar systems are used primarily to detect noise from marine objects (such as submarines or ships) and marine animals like whales. Unlike active sonar, passive sonar does not emit its own signal, which is an advantage for military vessels that do not want to be found or for scientific missions that concentrate on quietly 'listening' to the ocean. Rather, it only detects sound waves coming towards it. Passive sonar cannot measure the range of an object unless it is used in conjunction with other passive listening devices. Multiple passive sonar devices may allow for triangulation of a sound source."
Now, to the cases of sonar and the Loch Ness Monsters. In December 1954, the crew of the Rival III fishing vessel had a curious encounter on Loch Ness. None of them caught sight of a Nessie – at least not visually. What they did do, however, was to track on their sonar equipment a large, unknown object which shadowed the boat for a distance of around two and a half thousand feet and at a depth of approximately 480 feet. Precisely what it was, was never determined. It’s worth noting that 1968 was an important year in Nessie history, too. That was when Professor D. Gordon Tucker, from the University of Birmingham, England achieved something notable at Loch Ness. He offered his help to the Loch Ness Phenomena Investigation Bureau, which undertook on-site investigations at Loch Ness and, at one point, had more than one thousand members. Specifically, Tucker provided the Nessie hunters with a prototype sonar device that had the ability to sweep underwater to a distance of no less than 2,500 feet. Significantly, when deployed – at a below surface level at Urquhart Bay’s Temple Pier – the sonar tracked a number of approximately twenty-foot-long objects traveling from the lower levels of the loch to the higher levels and vice-versa. They were never formally identified.
Operation Deepscan was a highly ambitious October 1987 effort to seek out the Nessies with sonar and which just may have had some degree of success. No less than two dozen boats were utilized to scan the depths of Loch Ness with echo-sounding equipment. Some of the presumed anomalies recorded were actually nothing stranger than tree-stumps. Others may have been a seal or two, which had wandered into the loch. Nevertheless, there was a moment of excitement when something large and unidentified was tracked near Urquhart Bay and at roughly 600 feet below the surface. It prompted Darrell Lowrance, of Lowrance Electronics – whose echo-sounding equipment was used in Operation Deepscan – to say: "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."