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24 January 2014

The underwater sights of the Cornish sea bed

Everyone knows about the sights you can see when you stay at holiday cottages in Cornwall, but the county has plenty of hidden sights too – and they’re just as spectacular as the view from the Minack Theatre or across St Ives Bay.

One of the great views of Cornwall is the Pendennis Headland and the Fal estuary from above. And lurking just under the surface of the sea and river there are some amazing sights.

The creeks and tributaries of the Fal hide some diverse and intriguing wildlife, which can be explored through the Cornwall Area of Natural Beauty organisation.

So what are the best five sights lurking under the waves near Falmouth harbour?


The sea and river bed around the St Mawes Bank lies a huge red bed of calcified seaweed, known as maerl.

The striking colours will take your breath away as you look at the mattress seaweed, which is home to a host of sea creatures.

The 700-year-old strip of seaweed is one of the largest in Europe and fossils found there date back more than 2,000 years.

Hermit Crabs         

The maerl provides a home to thousands of hermit crabs, who spend their lives scuttling around the seabed.

To survive in the maerl, which also draws predators close to shore, some crabs cover themselves in sponge, sea weed and even other life forms. It’s not unusual to see hermit crabs lurching around the maerl with sea anemones attached to their backs – the ideal camouflage.


The large patches of eelgrass which exist in the Fal Estuary and Helford River are also protected and form huge sub-aquatic pastures inhabited by hundreds of varieties of animals.

Basking Sharks

These massive herbivores of the deep can reach as big as 10 metres long and weighing up to two tonnes – giving them a terrifying underwater look.

But the sharks, the second biggest fish in the world, are completely harmless and are drawn into the Cornish cost to feast on plankton.

Nonetheless, it can be exhilarating to watch their fins slice through the water, or watch from the sea bed as they cruise with their huge mouths open.


Most people know cuttlefish as those things you put in birds cages for them to peck away at – which might make you think they’re relatively harmless little animals.

In actual fact though, they’re deadly predators in the Fal estuary, eating crabs, shrimp, fish, octopuses, worms, and even other cuttlefish.

Their cuttlebone gives them a hard inner shell which makes them tough and interestingly they have one of the biggest brain to body size ratios of all invertebrates.



To see these sights during your stay at holiday cottages in Cornwall visit Atlantic Scuba’s website.

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