More than two hundred people turned out to a 'supporters stroll' against proposed plans to put 10 houseboats on Grasmere.
Owners of the lake, Lowther Estates, is seeking clarification from the Lake District National Park Authority, about whether it needs planning permission to put the boats on the lake.
'Houseboats OFF Grasmere' say it would ruin the tranquility of the area, and set a precedent for other, smaller lakes.
The Chief executive of Lowther Estates says the ten yachts they wish to put on Grasmere will "fit in with the landscape just as they do on Ullswater and Windermere".
Andy Astle, from the group Houseboats Off Grasmere, said: "In terms of difference, 10 houseboats and six people on each boat at the height of summer that's 60 people, mooring anywhere on the lake as they're not going to be statically moored.
"They can move around at will, the noise, the potential pollution it could be horrendous. It is going to destroy the main reason that people come and enjoy the beauty of Grasmere."
Angela Clarke, who owns a guest house in the area, believes the plans should not be allowed to go ahead. She said: " We've had guests come to our guesthouse for 40 years and they all come to Grasmere for one reason - to enjoy the peace and tranquility it offers.
"These boats would ruin that and potentially cost us business but more than that it could set a precedent across the national park.
"There are some lakes where we expect to see boats but Grasmere should not be one of those it is simply too small and the impact would be too great
In a statement the Lake District National Park Authority stressed this was not a planning application. They said: "In this lawful development certificate application the applicant and their advisors put forward a case that an application for planning permission is not required for what they propose.
"As local planning authority we must decide whether this is the case or not as a matter of law."
Andy Astle met with Lowther Estates CEO, David Bliss on Monday 6 January. 'Houseboats OFF Grasmere' described the meeting as "friendly [but] completely unproductive."
Another protest march is planned for Saturday 1 February.