Emerging from the mist with oily black skin and three eerie humps, this picture reveals a mystical looking beast gliding through the lake.
The snap was taken on a camera-phone by terrified IT graduate Tom Pickles, 24, who said an animal the size of three cars sped across the lake in front him last Friday.
'It was petrifying and we paddled back to the shore straight away,' he said.
'At first I thought it was a dog and then saw it was much bigger and moving really quickly at about 10 mph. Each hump was moving in a rippling motion and it was swimming fast.'
This is believed to be the eighth sighting of a long hump-backed creature - affectionately known by locals as Bownessie - in the past last five years.
Mr Pickles, who said he watched the creature for 20 seconds, added: 'I could tell it was much bigger underneath from the huge shadow around it.
'Its skin was like a seal's but its shape was completely abnormal - it's not like any animal I've ever seen before.'
Mr Pickles's companion Sarah Harrington, 23, said: 'It was like an enormous snake.
'It freaked us all out but it wasn't until we saw the picture that we thought we'd seen something out of this world.
'I only saw it for a few seconds but all I could think about was that I had to get off the lake.'
The pair - who both work for Shrewsbery based IT company CapGemini - were on the last day of a team building residential training course at Fallbarrow Hall, Bowness, Cumbria.
They had kayaked 300m out into the lake near Belle Isle when they spotted the monster to the south.
Mr Pickles's picture perfectly matches the description of an earlier sighting from the shores of Wray Castle in 2006 by journalism lecturer Steve Burnip.
He said: 'I'm really pleased that someone has finally got a really good picture of it.
'I know what I saw and it shocked me, it had three humps and it's uncanny the likeness between this and what I saw five years ago.'
Monster hunter Thomas Noblett and TV psychic Dean Maynard said this new sighting has fired up their enthusiasm for another search.
The pair have twice scoured the lake with sonar equipment looking for Bownessie, but to no avail.
'We're convinced there's something down there and were going to get straight back out on the water,' said Mr Maynard.
Photo expert David Farnell of Farnell's photographic laboratory in Lancaster, said he couldn't rule out a hoax but this is the best quality image of Bownessie he'd seen.
He said: 'It does look like a real photo but because its been taken on a phone the file size is too small to really tell whether it has been altered on Photoshop or not.'
Sceptics remain unconvinced that something that size could exist in the 11 mile long lake.
Nigel Wilkinson, director of Windermere Lake Cruises, said his boat crew had over 100 years experience out on the water in all conditions and hadn't spotted anything unusual.
He said: 'We carry 1.3 million passengers - that's is 2.6 million eyeballs - and none of them have ever brought Bownessie to our attention.
Dr Ian Winfield, a lake ecologist at the University of Lancaster, said it was highly unlikely that an animal as large as three car lengths could survive in Windermere.
'It's possible that it's a catfish from Eastern Europe and people are misjudging the size but there is no known fish as large as the descriptions were hearing that could be living in Windermere.'
'We run echo sounding surveys every month and have never found anything.'
The mysterious aquatic beast is starting to draw parallels with the infamous Loch Ness monster for drawing even more tourists to the Lake District hot-spot.
Ellis Butcher from Cumbria Tourism said: 'The truth is Windermere and Bowness are incredibly popular destinations and don’t need gimmicks to get people to visit.
'Nonetheless at the start of the tourism year, it doesn’t do the industry any harm to have this kind of profile across the media.'
Read more: http://www.dailymail.co.uk/news/article-1357987/Has-Bownessie-caught-camera-couples-close-encounter-car-long-beast-Lake-Windermere.html