Harry Redknapp has proved the doyen of wheeler-dealers in his managerial career, but even he was left stunned by Portsmouth’s plan to swap their present cowshed for a £600 million stadium that will enable his players to walk on water.

The club have planned to redevelop Fratton Park for years, one scheme involving turning the pitch 90 degrees, but that idea has been shelved for a state-of-the-art development built on a platform in the sea. According to Redknapp, the facelift for the 13-acre site by the city’s dockyards will enable Portsmouth to become a football powerhouse.

“If we stay where we are, we are relying on Mr [Alexandre] Gaydamak [the owner] putting his hand in his pocket every year,” Redknapp said. He insisted that this would not prove another false dawn. “The owner we have got will see this through,” he said. Nevertheless, the club do not expect to submit a planning application until August and the team will not play there until 2011.

The plans have been drawn up by Herzog & de Meuron, the Swiss architects who designed London’s Tate Modern, Beijing’s Olympic Stadium and Munich’s Allianz Arena, and include a 36,000-seat stadium with 1,500 apartments. The £600 million figure is the estimated worth of the site after completion, but Peter Storrie, the chief executive, said it would not cause the club to empty their coffers.

Instead, the sale of Fratton Park for 750 homes will bring in about £30 million and there will be revenue from developing the waterfront and selling naming rights. “It will cost very little,” Storrie said. “This is a purely stand-alone development. Alexandre has already invested heavily in the squad and will continue to do that.”

Gaydamak refused to say how much he would be investing and denied that such a project had been his ambition since arriving on the South Coast last year. “It’s very impressive and hopefully we will achieve it,” he said. “I always envisaged Portsmouth being a big club. Am I proud? Of course. Am I happy? Of course. Do I want to improve the team? Of course I do.”

Bold as the plans are for the 13-acre site, which is partly Crown land, the lingering problem of planning permission remains, which is why Portsmouth have gone big on the fact that the stadium would regenerate the area and be a significant asset to the city. “This has the wow factor and if we want to move on and become one of the big boys we have to do it,” Storrie said.

Redknapp also dismissed the notion that sentimentalists would balk at the radical rehousing of their club. “Teams make atmospheres,” he said. “They say it’s special at Fratton Park, but eight years ago they were getting 9,000 against Hull.” At the new bowl, fans will remain close to the pitch and the modest capacity has been set at a level to retain Fratton Park’s intensity.

Given its location and the prospect, Storrie said, of up to 20 per cent of supporters travelling to the ground by boat, the joint venture between Portsmouth and the Sellar Property Group ranks as one of the most ambitious in British stadium history. It has happened quickly, Redknapp admitting that he became aware of the plans only a fortnight ago.

Cynics will wonder about the £600 million figure – the Emirates Stadium cost Arsenal £390 million – and doubt whether people will really want to live in a football stadium. There is also the matter of moving HMS Warrior, which sits on the site at present, but the club and Sellar insist that they will preserve all historic features.