The mystery of the fabled Loch Ness monster endures despite a weekend of mass-participation Nessie hunting.

About 200 volunteers kept a lookout for mysterious events from the shoreline, but spotted nothing unusual.

Observers on a boat using acoustic equipment reported four unidentified “gloops” but then realised their recording device wasn’t plugged in.

Organisers said visitors from around the world joined the hunt despite appalling weather.

Alan McKenna, from volunteer research group Loch Ness Exploration, was on a boat using a hydrophone system to capture the underwater sounds of the Highlands loch.

He said when they were testing the system on Friday, they heard four distinctive “gloops”.

“We all got a bit excited, ran to go make sure the recorder was on and it wasn’t plugged in,” he sheepishly admitted.

The first written records of monster date from the 7th Century when a chronicler told how many years before, the Irish monk St Columba had banished a water beast from the River Ness.

The modern legend began in 1933 when hotel manageress Aldie Mackay claimed to have seen a whale-like creature in the loch.

The following year the famous “surgeon’s photo” captured what looked like a prehistoric beast in the water, though 60 years later it was exposed as hoax involving modelling clay and a clockwork submarine.

The old hotel building at Drumnadrochit where Aldie Mackay reported her famous sighting is now home to newly-revamped Loch Ness Centre which jointly organised this weekend’s hunt with Loch Ness Exploration.

As well as bedraggled volunteers on the shore, hundreds more monster hunters took part from more comfortable surroundings, by watching webcams trained on the loch.

“We’ve had people from Spain, France, Germany and we had a Finnish couple. We’ve had news teams from Japan, Australia, America and it has been really good,” said Mr McKenna.

“We’ve all kind of banded together. It’s been fantastic.”

Loch Ness Centre manager Paul Nixon was adamant the event – billed as the biggest Nessie hunt in 50 years – was more than a publicity stunt, and said it showed that fascination with Nessie was as strong as ever.

“I believe there is something big lurking in the depths of Loch Ness,” he said.

“Now I don’t know whether it’s a monster – I don’t know what it is but I reckon there’s something down there.”