SCUBA magazine editor Simon Rogerson, gives us a glimpse of what he describes as the “true jewels” of the isles.

Lying 28 miles south west of the Cornish coast, the Isles of Scilly have a unique marine ecosystem, fed by the nutrient-rich water of the open Atlantic. The islands and offshore reefs form a dynamic mosaic that is home to wonderful species of fish, invertebrates and marine mammals. These islands are legendary among divers, who visit to experience the dramatic reef walls, or perhaps to connect with the past by visiting shipwrecks.

These waters are the final resting place of HMS Colossus, which was driven aground in a gale while returning from the Battle of the Nile in 1798. Today the wreck’s debris trail is a living museum, where brightly coloured ballan wrasse swim between cannons and other artefacts.

Thanks to the location and lack of pollution, the water here is unusually clear and supports a swaying forest of kelp to a depth of about 18 metres. It’s in this zone where you are likely to encounter one of these island’s most likeable inhabitants, the Atlantic grey seal. These impressive pinnipeds are hardy mammals that favour harsh offshore environments, but in the warm climate of Scilly their mood seems to soften and they are known for the games they play with visiting divers and snorkellers – their favourite trick is to sneak up behind you and gently nibble on your flippers.

As you venture deeper, the granite walls of the reef become dominated by fields of anemones, forming an ecosystem that supports many different creatures. The pale light does not reveal their natural lustre, but if you shine a torch onto the reef you will see it come alive in vivid shades of red and yellow. If one had to choose a single marine creature to represent the Isles of Scilly, it would be the humble jewel anemone, Corynactis Viridis. Individually these tiny anemones seem insignificant, but when you see colour-coordinated colonies covering great swathes of rock, the effect is profound. Their capacity for prolific budding (or asexual reproduction) means that specific colours dominate patches of rock, as different colonies vie for space on the reef. They form a sort of living wallpaper, in every imaginable hue. The Isles of Scilly have seen their share of treasure hunters over the years, but surely the true value of these islands lies in the wealth of nature they support, above and below the waves.

During a visit to the islands, you can enjoy the company of experienced guides and dive amongst the ocean’s buried treasure, vibrant reefs and colourful variety of abundant marine life. Or simply enjoy Scilly’s underworld from the comfort of a lecture hall at the weekly dive lectures hosted on St. Mary’s.