A cruise company is to fit sonar equipment to its flagship boat in case it passes over the Loch Ness Monster.

Jacobite – Experience Loch Ness demonstrated the search gear at VisitScotland Expo 2007 at the Royal Highland Centre in Edinburgh.

The company has had a fake video made of Nessie swimming across a sonar screen to illustrate how it would work.

The equipment will be fitted to the Jacobite Queen which takes tourists on cruises around the loch.

Freda Rapson, owner of Jacobite, said: "We've taken a genuine sonar scan and, with the help of technical experts, added what every visitor to the Loch hopes to see - Nessie.

"It's been a while since the last sighting of the Loch Ness Monster. That could be about to change, though, now the Jacobite Queen's got sonar aboard."

Unexplained sightings of "something" in Loch Ness date back to the 6th Century. Various theories have been offered to what the monster could be. They include it being from a group of extinct marine reptiles called plesiosaurs, which used two sets of powerful flippers for swimming.

In 2006, a scientist suggested the monster may have been an elephant.

Neil Clark, curator of palaeontology at Glasgow University's Hunterian Museum, spent two years researching Nessie.

He said sightings could have been of circus elephants, as fairs visiting Inverness would often stop on the banks of Loch Ness to give the animals a rest.

The trunk and humps in the water would bear similarities to some of the most famous Nessie photographs.