Wild Swimming in Pembrokeshire

Sea swimming in Pembrokeshire is very good and very cold. The water sits somewhere between 8 and 15°C for most of the year, peaking in late August and September, and the beaches that look most inviting are not always the ones you should be getting into.

The sheltered south-coast bays are the classics. Barafundle has no road to it and no facilities, which is why it still looks the way it does, and the swimming is superb on a calm day — clear water, sand underfoot, and a walk in from Stackpole Quay that filters out the casual. Broad Haven South next door has Church Rock offshore to swim towards, though it is further than it looks. Stackpole Quay itself is a tiny National Trust harbour with steps into deep, clear water and is a favourite with local swimmers precisely because you can get in without wading.

On the north coast, Cwm-yr-Eglwys and Pwllgwaelod sit either side of Dinas Island and offer sheltered water in almost any wind — if one is choppy, the other won't be, and the flat valley path between them takes ten minutes. Abereiddi's Blue Lagoon is the strangest swim in the county: a slate quarry breached to the sea when the workings closed in 1910, deep, still and a peculiar green. It is a coasteering and cliff-diving venue, so expect company and do not jump from the walls unguided.

For lifeguarded swimming in season, Whitesands near St Davids, Tenby's beaches and Dale are the sensible choices, and if you are new to open water you should be using them rather than a deserted cove.

A swim here is usually shorter than you plan. Ten minutes is a good swim in May. Twenty-five is a long one in September. The pattern most regulars settle into is get in slowly, swim parallel to the beach rather than out from it, get out before the shivering starts, and spend as long getting warm afterwards as you spent in the water.

Late July to early October is the comfortable season, and September is the pick — warmest water, empty beaches, and the summer crowds gone. Year-round swimming is a real and thriving thing in Pembrokeshire, but it is a habit you build up to over a whole autumn rather than start in January.

What catches people out: cold water shock, every time. The gasp reflex is involuntary, it happens in the first thirty seconds, and it is why people who could swim perfectly well drown. Walk in, breathe out, wait. The second is tidal cut-off — several of the small coves here have no exit at high water and the tide comes in behind you while you are looking at the sea. The third is the assumption that a calm-looking bay has no current. The edges of bays, where water drains back out, are where the rips run.

Take a tow float. Swim with someone. Warm clothes in the car, not in the rucksack on the beach.