AFTER more than a quarter of a century working for the family business John Thornton, the grandson of the founder of Somercotes chocolate-maker Thorntons, was in no mood to spend his retirement pruning the roses.

Instead, the 66-year-old decided on a rather larger undertaking – to turn a 70-acre site near the South Derbyshire village of Willington into one of the country's largest marinas for canal narrowboats and cruisers.

Despite his decision not to retreat to a quieter life in his garden, John admits that he has a passion for growing things, namely businesses.

In the early 1980s when he became chief executive of Thorntons, the company's profit was around £1 million.

Throughout that decade the business grew into a major retailer with profits of £12 million.

John said: "It was never pre-ordained that I would go into the family business, it just happened.

"The 1980s and the early 1990s was a thoroughly enjoyable time for me as the company went through rapid growth.

"I am the sort of person who likes to grow and develop a business."

After Thorntons, he moved into the leisure industry.

In the early 1980s, John, along with his cousin Michael Thornton, had bought an area of land near Willington, close to the Trent and Mersey Canal.

Underneath the pasture, the land was rich with gravel, which was extracted to help build the nearby A50.

The pits were flooded to create a fishing lake but it was a struggle to make this economically viable.

John and Michael had to think of something else.

"Somebody suggested that we turn it into a marina serving the canal," said John.

"I confess that, at the time, I said it could not be done. I thought it would be too expensive.

"One issue was that we had to build a channel connect the marina to the canal, which would involve the narrowboats going under the Willington to Findern road.

"I also didn't have any knowledge of canal narrowboats. Sailing had always been my passion.

"But the numbers seemed to add up. If they hadn't, we never would have gone through with it.

"What also helped was that South Derbyshire District Council was very receptive to the idea because it would create jobs and boost the economy."

Madecorn Leisure was born and plans were submitted to the council for a 585-berth marina.

The project cost £7 million, including £500,000 from the East Midlands Development Agency's Waterways Regeneration Fund, and support from RBS.

Work began in January, 2008,

The development, called Mercia Marina, opened in September that year and has been growing ever since.

John said: "Narrowboat-owners are a very dedicated and passionate community.

"Geographically, its central location is ideal.

"And people can keep their boats here all year round because the marina is security protected.

"We have invested in the very best facilities so they have everything they need."

As well as the berths, the marina has a tearoom, chandlery, dry dock, fuelling quay and boat hire and sales.

There are only 150 of the 585 berths left.

John said: "I'm delighted with the success.

"Many people have moved their boats here from elsewhere.

"I believe this is a combination of the facilities and competitive prices.

"No industry is totally recession-proof but I have found that the narrowboat market is continuing to hold up well."

Madecorn is now in the process of adding to its facilities.

It has recently gained permission for a £2.5 million hotel, spa and gastro pub development which will create up to 50 jobs. Work on the development, called the Lighthouse, is expected to start next year for a 2012 opening.

The marina also has permission for 18 holiday lodges. The show lodge has already been sold and another has also been snapped up.

John said: "Our aim is to continue to develop the site. The marina is bringing economic benefits to the area, not just through the people who are directly employed here, but because holidaymakers are being attracted to the area from across the country and abroad.

"The idea is to create a marina that is used the whole year round.

"Of course, it's important never to lose sight of the fact that our core customers are the narrowboat-owners and they should and will always come first in any of our plans.

"But there is also room to create a place that attracts all types of holidaymakers.

"For example, the people who are interested in buying one of the lodges do not necessarily have to own a narrowboat.

"We're also keen to provide facilities that are of benefit to the community."

Although he has gone past retirement age, John said he has no intention of taking a narrowboat and chugging away into the sunset.

He said: "I thoroughly enjoy what I do. I'm here at the marina a couple of days a week, so I feel I am achieving a balance.

"Looking back, I wish I had started this project earlier because I enjoy it so much."