WHAT do you see when you look at the sea? If you are abroad, or even in the South- West of England, it will probably be water which is blue, warm and inviting.

But a survey has shown Northerners are more likely to look on the North Sea as cold, dirty and barren.

Now, Natural England has produced a series of fascinating and colourful maps showing just how rich and varied the landscape and life is below the North Sea waves.

Sunken Neolithic and Roman villages are reminders of how the coastline has changed down the centuries. The remains of up to 50,000 mammoths have been trawled from the seabed off the North Sea coast, along with bone harpoons, flint arrow heads and axe heads showing how extensive life had been before the land was submerged.

Elsewhere, the huge sand dunes of the Dogger Bank teem with sand eels and reach the height of Nelson’s Column.

Other expanses of sand hills and plains provide a hunting ground for thornback rays, diving seabirds, porpoises and even whales.

Underwater gullies, cliffs and sea caves around the Farne Islands have huge areas of kelp forests, where grey seals play and fish – and where they are sometimes hunted themselves by the odd killer whale.

To the south of the region, underwater caves and chalk pillars off Flamborough Head have their own particular characteristics, along with the sandy mouth of the Humber.

Martyn Howat, Natural England’s North-East regional director, said the varieties of landscape and wildlife were outstanding.

“There are dramatic landscapes with valleys, hills, plains, and cliffs which are a source of intrigue and fascination,” he said.

“There are all these great places under the waves and yet most people have no idea that they are there.”

The great North-Eastern rocky reef stretches all the way along the Northumberland coast to Scotland, reaching 20 miles out to sea.

It supports a rich diversity of life, including large numbers of pinkwhite Deeplet anemones, crabs, sea urchins, lobsters and fish such as the red and blue cuckoo wrasse, the pollock and – in dark crevices – fearsome-looking, but totally harmless, wolf-fish.

Others with intriguing names are light bulb sea squirts, lumpsuckers, ballan wrasse and bottle brush hydroids.

Large areas of gravel support huge beds of brittlestars, a kind of starfish which lie in dense numbers and catch passing food by waving their arms around.

Elsewhere, 3,600 grey seals – threequarters of the English population – live off the North-East coast, mostly on the Farne Islands.

There are also small populations of harbour or common seals on Lindisfarne and at the mouth of the River Tees, where they can be watched from Natural England’s Teesmouth National Nature Reserve.

The marine maps are part of Natural England’s undersea landscapes campaign, which aims to encourage people to find out more about the richness of their local seas.

Although there were more than 20m trips to the seaside in England in 2007, very few people have any idea of what lies beneath the water.

A survey commissioned by the National Trust found that, last year, 62 per cent of the population had been on a day trip to the coast or seaside – compared to 41 per cent who had visited a stately home – and 50 per cent had enjoyed a seaside or coastal holiday.

Ninety-three per cent said they simply looked at the sea and relaxed, while 89 per cent walked along the coast.

But, asked about their perceptions of the sea, there were distinct regional differences.

Northerners tended to think of the North Sea as dirtier and colder than waters off other parts of the country, and cited industrial pollution as a factor.

They believed murk meant dirt, even when they accepted that sand and tidal movements could play their part.

The North Sea was seen as second best compared to the South, particularly the South-West.

Those in the South and South- East regarded their sea as busy shipping-wise, but secret beauty spots and some good environmental stories gave a feelgood factor.

People in the South-West knew that they were considered lucky by others, who generally think their sea is warmer, cleaner and richer in wildlife.

As part of the undersea awareness campaign, Natural England held a series of free events throughout the summer and more are planned next year.

They involved children making undersea landscapes, model basking sharks, crab door guards, cuttlefish finger puppets and murals.

An 81-year-old who watched her grandchildren taking part said she had learned more about the sea in 45 minutes than she had in a lifetime of living beside it.

Mr Howat said it had been fantastic to see people having fun and finding out what exists under the sea. “You see their faces light up and they want to learn more,” he said.

The UK is committed to delivering a network of Marine Protected Areas around its coastline by 2012.

They will give various degrees of protection to undersea landscapes and marine life, and Natural England will play a key part in delivering them.

● More about Natural England’s campaign and its regional maps can be found at www.naturalengland.

org.uk/campaigns/marine.