Great North Swim: Why open water swimmers love Windermere

Swimmers set off in waves of about 350 to avoid congestion

Thousands of swimmers are swapping changing rooms and chlorine for the al fresco delights of an open water event around Windermere in Cumbria's Lake District this weekend. Why?

When the Great North Swim was first held in 2008, there were 2,200 participants. Now that figure has grown to nearly 10,000.

Back then, they were a select band of serious enthusiasts swimming a mile around the lake.

These days the open water swimmers tackling the half-mile, one mile, two mile and 5km courses are not all super-fit thrill-seekers.

Like "fun" half-marathon runners, many have the slightly over-excited demeanour of someone doing something quite a long way outside their comfort zone.

They swap nervous stories about leeches and swan mess and discuss the relative merits of bare feet (cold but fast) versus rubber socks (warmer but prone to waterlogging and slower).

Deborah Stocken's swims have become a social event, with friends from around the country meeting at Windermere

Participant Deborah Stocken, 44, is a senior lecturer at Newcastle University.

Although she is fitter than many, the dark depths still give her pause for - slightly panicked - thought.

"It's what you can't see underneath you," she says.

"You know when you're swimming in a swimming pool you can always see the bottom? It's not being able to see the bottom.

"It's the blackness - that's what used to make me hyperventilate."

The cold does not bother her. Or, at least, not enough to stop her swimming the aptly-named Big Chill Swim in the autumn months.

Even the wildlife does not put her off.

Training at the Queen Elizabeth lake at Woodhorn, Northumberland, she spotted some centimetre-long black marks on her foot. Leeches.

"I was rinsing my wetsuit, standing it under the shower hose and just rinsing it down, and these little leeches were falling off the bottom of my wetsuit into the bottom of the shower.

"I thought, I've got to stop rinsing my wetsuit in the shower."

More than 10,000 swimmers descending on the Lake District, bringing family and friends, has "a real economic benefit" for local businesses, tourist board Cumbria Tourism believes.

Project manager Andrea Runkee says the event has "firmly established itself as being one of the county's key attractions in the annual events calendar".

Great Swim director Alex Jackson says there are "very robust" procedures to keep the mix of professional swimmers, confident amateurs and complete novices safe.

"Wetsuits are compulsory for our events," he says.

"They give you buoyancy and they also give you warmth - and we have kayakers that line the entire course.

"We literally have people who hop from one kayak to the next - just a break and a chat with the kayaker and move on."

Dr Stocken said swimming in open water was "a bit nerve-wracking because it was pitch black"

Organisers also have a tracker system so they are sure all the swimmers who go in the lake come out again.

On a sunny day the drop-out rate is less than 1% - rising to about 3% in windy weather.

Being hauled out halfway is something another entrant, Newcastle University health researcher Nikki Rousseau, 45, wants to avoid.

"The first time I was just keen to get round," she says.

"Then last year, and this year as well, there's as bit of me that would like to beat my time.

"But, I think, by the time I get in the water again I'd just be pleased to finish and not end up in a canoe."

An outdoor runner and "not a great fan of the gym", she found training for the Great North Run and Races for Life provided a "reason to go out on a rainy day" and wanted something similar for swimming.

Open water swimming is more a psychological challenge than a physical one, even for strong and regular swimmers, she believes.

Open swimming once a year is "enough" for Nikki Rousseau

"The cold - when it's very cold it can take your breath away - and just the murkiness of the water and it smells and you don't necessarily want to put your face in the water," she says.

"One time I was swimming along and a swan flew down very near me.

"That doesn't happen in the swimming pool."

With swan excretions also a hazard it seems best not to think too closely about what you might be swallowing.

Water quality is monitored and swims have been cancelled because of blue-green algae in the water but the word among open swimmers is that a can of cola drunk straight afterwards is "supposed to kill anything" you might have ingested accidentally.

Dr Rousseau is not convinced, but drinks it anyway.

The number doing the longest course - 5km - has doubled since last year

Dr Stocken entered the 2012 Great North Swim as a challenge to raise money for a friend facing kidney dialysis.

She has been entering open water events around the country ever since.

Despite being surrounded by a lot of competitive swimmers she always pauses, halfway round, to take in the view.

"On a day when it's absolutely tipping it down with rain, you'll have mist across the lake and you know you're surrounded by mountains but you can't see them.

"My friend and I are very good at making ourselves stop, just for literally five seconds, and think 'Oh my God, I'm in the middle of the lake with swans.'

"It's a fantastic feeling."

The Great North Swim is followed by the Great East Swim at Alton Water, near Ipswich on 20 June, the Great Manchester Swim at Salford Docks on 4 July, the Great Newham London Swim on 18 July and the Great Scottish Swim at Loch Lomond on 29 August.