A 10mph speed limit has finally come into force on Windermere - ending a process stretching back almost 15 years.
The limit came into force at midnight on Tuesday
The aim is to bring calm to the lake's waters, but it continues to whip up a storm of opinions.
Supporters say the limit will remove conflict between lake users, create a tranquil atmosphere and will recapture Windermere's place as the "jewel in the crown of the Lake District".
But opponents say they have nowhere else to water-ski or use power boats, there was no real conflict between users and are concerned about the impact on Windermere's atmosphere and economy.
Keep Windermere Alive Association secretary, Kevan Furber, said: "I am passionate about it. Why can't we manage it for everyone?
"The enjoyment is being taken out of using the lake. The most fantastic thing in the world is to be out on the lake first thing when it's quiet, having a ski, then handing it back to the other users.
Protestors say the plan will hit the local economy
"They are taking something away from us which is very valuable."
He said he believed it would create a "museum or mausoleum" instead of somewhere for people to enjoy themselves.
Campaigners say they are bemused by the limit, saying all that is needed is a managed solution which would involve powered craft users being looked after by a governing body.
They say they want to use just 1% of the Lake District and there is nowhere else to go and that the authorities will not discuss the issue.
Tony Kemp from Windermere Action Force believes the limit has not been properly thought out and will backfire.
He says boats being forced to travel below 10mph, which they are not designed to do, will create 3ft or 4ft waves, creating problems for other users.
He believes power craft users will head back to three other lakes - Coniston, Ullswater and Derwentwater - where there is also a 10mph limit but public rights of navigation, and the authorities will have to manage four instead of one lake.
National park officials say a speed limit is needed on the lake
Mr Kemp believes the limit will be broken and a list of events for the coming year feature on WAF's website. He is in the process of appealing after being found guilty of breaking the speed limit on Coniston.
He said: "People are being criminalised in short for practising a healthy family sport.
"It is such a vibrant lake with people sailing, canoeing and waterskiing, having fantastic family fun and doing that at the same time in harmony.
"There's a lot of anguish, anger and bad feeling."
But the Lake District National Park Authority, which intends to enforce the limit by collecting evidence using digital video equipment, still cameras and a laser gun, believes it marks a new future for Windermere.
Authority spokesman Mick Casey said: "We are very confident about it. We have just produced a new management strategy for it.
"I think many people thought the arrival of jet skis took some of the shine off Windermere. With their departure, Windermere will once again start to be that jewel in the crown of the Lake District."
He stressed the limit, which only applies to power-propelled craft, was not a ban.
'Interfering with balance'
The bylaw was confirmed in 2000 following a public inquiry, but it was suspended for five years to give businesses time to adapt, the Authority said.
Friends of the Lake District's policy director Ian Brodie shares the view Windermere will be "restored to the heart of the Lake District".
He said the limit was needed to cut the disruption to other lake users, such as anglers and canoeists, and ensure their safety.
He said: "We are delighted for people who live around the lake.
"We expect Windermere to be as economically buoyant. I think there will be more people who come to Windermere because of the restoration of its special qualities."
But Tony Rothwell, managing director of boat firm Shepherds, says he has not expanded in the area over the last 10 years and is slimming down his Windermere base and four of his 28 staff have left this year, worried about prospects.
Mr Rothwell is a water-skier and a sailor and says both sports can go on without conflict.
He said: "They are interfering with the balance of the lake which has grown up naturally."