W Above : Nudibranch ( Polycera
quadrilineata ) feeding on bryazoan growing on a kelp blade was a stunningly beautiful dive site with an incredible amount to see . Squid eggs were twirled around swaying kelp fronds , top shells were hiding below . We swam out over the sandy bottom to find flat fish , scorpion fish and crabs . At around 30m there was a reef strewn with life in a myriad of colours including sun stars , sponges , anemones , tunicates and urchins . In between there were busy little hermit crabs going about their business and nudibranchs weaving their circular egg patterns across the rock face . Back up at the kelp line we saw dogfish and conger .
Tolsta Head
That afternoon we dived Tolsta Head – the first promontory south of the Butt of Lewis . The bay to the north was the site of top-secret biological warfare experiments in the early 1950s . This involved the release of toxic agents , such as bubonic plague , from the HMS Ben Lomond , a converted tank landing craft , and the assessment of the effects on animal subjects . The tests almost ended in disaster when a fishing trawler strayed into the area .
The area has now been designated as a Site of Special Scientific Interest due to its geomorphology – the science behind landscapes . Despite its history , this is without doubt one of the prettiest reefs I have ever dived . The rocks and boulders were hidden beneath a carpet of brittle stars . I was wondering where to point my camera when I had a feeling I was being watched , so I glanced over my shoulder and saw a guillemot swimming past . By the time I realised I had a bird peering over my shoulder at 20m , it was too late and I ’ d missed the shot .
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