With golfers on the cliff above giving me slightly odd looks, I struggle into my wetsuit and negotiate my way across a few slimy yards of seaweed-smothered rock.
I happened upon this spot after wandering over from the busy Ty Coch beachside pub. A rocky cove called Borth Wen, it was all but deserted, with mini-islands of igneous rock poking out of the water, creating a naturally sheltered bay – a promising place for a bit of aquatic exploration.
I push myself out into the cool Atlantic water and look down through my goggles. Being a landlubber, my occasional forays into marine ecology always feel exhilaratingly exotic. I find myself swimming above a sun-dappled seafloor carpeted in aquatic life, mostly comprising marine algae in all its strange, fascinating forms. Huge “tentacles” of Himanthalia elongata, sometimes called “sea spaghetti”, brush against my skin and softly tangle around my feet in a way that feels disconcertingly alive. Monstrous heads of oarweed (Laminaria digitata) cling to the rocks, their dark brown fronds waving in the current like serpents.
As the water deepens, the life grows in scale. I appear to have entered a forest of kelp: an order of large seaweed algae that can form dense, wildlife-rich underwater “jungles”. A small school of silvery fish scurries among the towering algae, a large spiny spider crab works its way across a rock and a sea trout lurks in the green depths.
I look up from this weird, wild world for a moment. On the coast above, people stroll past on the way to the pub and the golfers are pushing their trolleys around on manicured grass.
Then I notice what looks like a small rock protruding from the water nearby. The rock bobs up and down, which seems strange, then turns its whiskered head towards me. I find myself looking into the fellow mammalian eyes of a grey seal. The animal stays there for a good few minutes, seemingly unfazed by the awkward interloper in its realm, before resuming its business in the underwater world.
• Country Diary is on Twitter at @gdncountrydiary