SCUBA April 2023 issue 134 | Page 21

Becky Hitchin continues her geological tour of Britain ’ s coastline . Part 3 : The nation ’ s south and west
BECKYHITCHIN

As above , so below

Becky Hitchin continues her geological tour of Britain ’ s coastline . Part 3 : The nation ’ s south and west

So now we come to the part of UK diving that most people reading this article know better than me . But I ’ ll do my best .

Dorset . Swanage . Now I have to admit that the only time I ’ ve ever been to Swanage was when I was about 12 , on a family holiday . All I can remember was a shop with really good apple doughnuts , and lugging the family ’ s dinghy to the beach . So , this may be a slightly biased account of one of the most famous shore dives in the UK . If I took my knowledge of Swanage Pier from the pictures I ’ m always amazed at in my Facebook account , I would think that : ( a ) Tompot blennies have a collective modelling agency that farms out particularly photogenic examples to each photographer as they enter the water . And ( b ) the water sometimes seems to be some really strange shades of pink , yellow and orange . Of course , that might relate to the skill of all the photographers down there and their access to shiny new lens systems , and particular photographers liking filters on their shiny lens systems , but I choose to believe the former , and will expect exactly that when I finally manage to dive Swanage .
Devon and Cornwall - you ’ ll be pleased to know I have actually managed to dive in each of these counties . Devon , unsurprisingly I know best from the late lamented Fort Bovisand where I first realised how loudly dive instructors tend to snore , amplified by the echoing , arched roof dormitories .
But let ’ s get back to geology . Devon and Cornwall form the south-west tip of the UK and are lands of two halves . Their north coasts are wilder and more exposed compared to the more sheltered southern coasts of clotted cream teas , wide estuaries and sheltered anchorages . The Scilly archipelago , off the south-west tip of England , encompasses both of these with shallow sandy sediments colonised by extensive eelgrass beds and reefs exposed to the full force of the Atlantic .
On towards Wales , via the wide Severn estuary . First – before we cross the border , we would have once encountered the late , lamented NDAC ( National Diving and Activities Centre , now the domain of secret projects ). Geology is pivotal for our quarry diving , as well as diving in the sea . NDAC was formed from a former limestone quarry which produced around 60 years of crushed rock for construction and agriculture , its depths and steep sides a result of that intensive activity . Quarries created from gravel dredging or chalk pits , by the way , tend to be shallower , with more sloping sides . A wander in from the shore rather than a jump off a floating platform because the rock being taken out just isn ’ t as strong as limestones or volcanic rocks .
In Wales , I want to take you to a dive

“ I wish I could say that visibility gets better as you head up the west coast of England ”

under a bridge . I wish I could say that I had a good experience of diving in the Menai Strait , but the last time I dived there , my buddy insisted on dragging me away from interesting sponges to show me pieces of kelp for the entire dive . I can however confirm that the North Wales kelp is excellent , but what most people dive there for are the numerous , large yellow and orange sponges that dominate the strait . Why is this dive possible ? As with many features we ’ ve seen , because of ice . Glaciers flowed down from Snowdonia exploiting underlying geological weakness and created a series of linear bedrock scours – the deepest of which became the Menai Strait .
I wish I could say that visibility gets better as you head up the west coast of England . But it doesn ’ t . From Morecambe Bay all the way up to the Clyde is sand and mud , strong tides and a potential long walk out – or back - across mud flats . When we get to the Clyde , we reach the biggest river input since the Mersey . This is another inherently industrial area , full of naval yards and top secret submarines , and while most of the well-known dives are wrecks , the more adventurous dive operators are discovering scenic shore and boat dives aplenty in the lochs and islands of the area . �
Porthkerris Cove on Cornwall ’ s Lizard peninsula , formed 400 million years ago when the area was completely submerged
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