F or many people, seaweed is nothing more than a blight on the landscape. Slimy, putrid-coloured weeds which cling to your legs as you enjoy a cool evening paddle.

Perhaps it's even the reason our seas look a murky brown, rather than a luscious clear blue.

And crabs are even worse – little nippers who deter the more wary beach-goer, odd-looking critters responsible for that well-known seaside stench. But for some, they prove a tasty culinary delight

Anyone who has ever tried seaweed will know that it doesn't come cheap. Order a box of sweet crispy seaweed at your local Chinese takeaway and not only will it set you back a few quid, chances are it's not even authentic seaweed – but cabbage.

There's nothing more quintessentially British than enjoying a fish and chip dinner on a beach in a windswept seaside town, and if you head down to West Bay in Dorset, you could swap this for a tasty stuffed crab. But again, nowadays, it doesn't come cheap. Unless you're John Wright.

John is best known as the River Cottage mushroom expert. With regular cameos on Hugh Fearnley-Whittingstall's River Cottage TV show he has proven his worth as a fountain of knowledge when it comes to wild food. And from the field to the shore, his expertise does not falter.

Like mushrooming, there are times of the year best suited to foraging for sea-based gems. But head out in spring time and you'll return with a basket bursting full of nutritious treats. "You get completely different things wherever you go," said John as the waves lapped at our boots on Weymouth beach. "Bowleaze Cove is very good for Sea Beet with other parts of Weymouth and Portland better for clams, shrimps and marsh samphire.

"Generally, the best time to forage is an hour and a half before low tide and up to an hour and a half afterwards."

At the beginning of our adventure these terms were as alien to me as the giant dulse which John pulled out of the water. The giant edible sample would have been much more suited to the set of some alien invasion blockbuster, rather than the Dorset coast. John said: "Wild food doesn't have to look good."

Looking at John in his wellies, waterproofs and hat it was clear I was going to struggle. Wearing a pair of leather boots and a skirt was not one of my brighter costume decisions but I managed, scrambling on rocks and tip-toeing through tide pools.

John said: "It's important to cut it off leaving about a third of the plant, allowing it to grow back. Scissors are best. I've been through hundreds of pairs in all the times I've been foraging."

Within minutes we spotted our first find, attached to a large concrete pillar at Bowleaze Cove in Weymouth. Hanging off rocks like rubbery handkerchiefs, Laver actually makes for a tasty meal. It's similar to the Nori seaweed used in a lot of Japanese cooking.

"It's an acquired taste," said John. "Fishy and savoury. And it takes about 10 hours to cook it, but I think it's worth it. Laver bread is just this cooked."

Seaweed is more versatile than you'd think and can actually be used as a vegetarian alternative to gelatine.

One of John's favourite recipes is Seaweed and Elderflower Panacotta made from Caragheen, an autumnal coloured leaf found in abundance all the year round.

Picking up a limpet, he said: "You can eat slipper limpets but they are very tough, they are best boiled down and used as a type of fish stock."

Gutweed looks highly inedible and not dissimilar to intestines with little air pockets full of oxygen. "It is the best seaweed for eating straight out of the sea," he said, handing me a sopping wet, bright green sample of the weed. "It's crunchy," I replied, only to be told that was probably sand. Oh dear.

But once I cleared the grit from my teeth, it was clear that Gutweed is not as rotten as it sounds.

"You can't really buy it," John said. "If you do, it's incredibly expensive. But it doesn't cost anything here. You can pick a hundred weight in a couple of hours. I dread to think how much that would cost in the shops."

So perhaps forays are a cunning way to beat the credit crunch.

John added: "The instincts for foraging and hunting are deep within us all and we have lost much in failing to fulfil these needs.

Everyone would enjoy wandering and paddling by the sea, looking for their supper, as this pleasure is written in our genes.

"You don't need to be an expert, you just need a good handbook and a little enthusiasm."

On the day of our trip, John's new book Edible Seashore was number 300 on the website Amazon, meaning that of the millions of books available to buy on the site, this one was the 300th most popular.

And it's not hard to see why. The beautifully bound book features everything you'd need to know about the basics of foraging on the coast.

Each page is accompanied by a wonderfully imaginative photograph and comes complete with an easy-to-read guide on various finds.

There are even some original and extremely tasty recipes to try.

■ The Edible Seashore, River Cottage Handbook No.5, is released by Bloomsbury and is available to buy in all good bookshops and online at amazon.co.uk with a retail price of £14.99