If you want to blend in with the locals in Cornwall, don’t buy all your clothes from J. Crew. It is the shop where “JDFLs” (Just Down From Londons) go when they are trying too hard to look the part. The JDFLs who have been coming from London for years will already know about this faux pas, and are faced with another dilemma: how to avoid looking as if they are trying too hard not to dress like JDFLs. This is rather difficult to achieve, because it depends upon arriving by boat rather than by car. As one born-and-bred resident puts it: “The authentic Cornwall look is slightly scruffy, slightly salty. For this, you need to sail.”

Sailing in will mean that you will also avoid the offputting drive along the A30, which explains why homebuyers in Cornwall want to own property as close to the coast as possible. “Cornwall is a place of extremes, and this is really evident on the drive along the A30,” says Jonathan Cunliffe, head of Savills’ Truro office. “Just south of Bodmin and Truro, the view becomes grim and remains so until you are west of Camborne and heading towards Penzance. Once you can see St Michael’s Mount and the coast — bang — you suddenly realise what Cornwall is all about.”

Cunliffe has lived in Cornwall since he was 3 and, not surprisingly, has some useful insights. He says: “There is stunning coastland but barren moorland; affluent yachties in the south and surfers and camper vans in the north; wealth on the coasts but unemployment and poverty farther inland.” These disparities are reflected in house prices. Cornish properties within 1km of the coastline are about 31 per cent more expensive than homes farther from the shore. Buy something within 100m of the sea, and that premium rises to 61 per cent. Sellers of mid-market homes that do not have the benefit of a prime location are likely to struggle in today’s market: these properties have taken a hit.

“Reductions from £700,000 to £500,000 are not unusual but even a 35 per cent discount might not be enough,” Cunliffe says. People who moved to Cornwall from London for the good life but found it financially unsustainable are now selling homes in this price range: “Many are now going back to London — to get proper jobs,” he adds.

Some stretches of the Cornish coast are more desirable than others, however. The uninitiated buyer should remember the golden rule: “estuary, estuary, estuary”, the Cornish version of “location, location, location”, according to Cunliffe, who says that if you buy near one, you are doing well. Fal, Camel, Helford and Fowey are all in this category.

Such is the demand for prime coastal homes in Cornwall that Cunliffe says the market has already bottomed out. This is because so few of these houses come up for sale — many are kept in the same family for decades. Savills recently sold one home in Trevose at its guide price of £3.5 million within two weeks; it had not been for sale since the 1930s.

It is this type of property for which Cornwall-loving celebs might pine. The area attracts famous people who prefer to “blend and hide” than live in the spotlight, Cunliffe says. Investors are also attracted; the jackpot for them is the unattractive Sixties bungalow, right on the shore, which can be knocked down and the land redeveloped to build something fabulous.

No one should ever dream of knocking down the home pictured above and below left, however. It is more likely to appeal to the sanctity-seekers. The property, Ropehawn, three miles from St Austell, came on the market last week at £1.5 million. It can be reached only by boat or by foot, which takes three minutes. “You can’t drive up to it in a Range Rover with your Waitrose bags,” says Guy Henderson, the owner. However, that three minutes is a small price to pay for what he describes as “total peace”.

Guy and his wife, Sophie, who come from Dorset, used to spend holidays in the house with their four children, but are now selling because their children are growing up and “family life has moved on”. The property has four bedrooms, three bathrooms, a guest cottage, two boathouses and walled gardens. It is well-sheltered and the sea is so clear that you can see to the bottom. “It was a wonderful era for us,” Guy says. “We would go there with another family or friends. There is so much to do. One group would be canoeing, another sailing to Fowey — an hour away by boat — and another fishing. We used to catch scallops, mussels and mackerel. We survived on what we had and life was simple.” He offers this advice to the prospective buyer, which sums up the lure of Cornwall: “It is a home that needs love, but it also needs an owner who is up for adventure.”

Ropehawn: Savills, 01872 243200

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