Strolling along the bank at Waveney River Centre all you can see beneath the big sky is miles of marshland.

It is this timeless view which is a precious part of what James and Ruth Knight sell at their holiday park Waveney River Centre, which last night added the EDP Tourism Awards' best Broads holiday experience to its litany of accolades.

That is why James, who is especially proud of his four David Bellamy gold conservation awards, is fiercely opposed to giant pylons marching through the Waveney valley.

Backing the EDP's Say No To Pylons campaign launched this week, he said: 'Everything we have tried to do is to maximise our location in the middle of a national park and on the edge of a site of special scientific interest which is also a nature reserve.

'We try to fit our business around the natural environment and, quite clearly, pylons would be totally incongruous and change the nature of what we have to sell.'

Fears that pylons could mar the landscape of the Waveney and Yare valleys have arisen following the publication of a document by National Grid. It shows a new 25-mile cable line running from Lowestoft to Norwich to feed power from the giant East Anglia One windfarm to be built off the Suffolk coast.

A National Grid spokesman said at the moment it was just a line on a map; detailed route options would be published in the summer and there would be full public consultation. However, father-of-two James, 44, said: 'While no route or methodology has been announced, I understand the fears. If someone were to build pylons across Carlton Marshes that would certainly have an adverse effect on our business.

'Part of what we sell is the beautiful big Norfolk sky, the open landscape and the chance to step back in time and get back to nature.

'At the moment, if you are in your holiday lodge or on our campsite, there are marshes as far as the eye can see – the march of high voltage cables across them would spoil the experience.'

James, whose family has invested a seven-figure sum in the park at Burgh St Peter, near Beccles, since they took over a run-down business in 2004, said it was ironic that efforts had been made to take down pylons and bury cables in some areas of the surrounding countryside.

The pylons that would be built under this major national infrastructure scheme would be much bigger and far more of an eyesore than the ones dismantled.

The centre's attention to the environment is shown by such features as its wildlife-friendly planting and a ferry service to the Suffolk side of the river to take visitors to Carlton Marshes nature reserve.

Former television botanist Mr Bellamy has a soft spot for the marshes which was the subject of his first PhD thesis.

'That is why we got him to come and launch our new ferry earlier this year,' said James.