February. Month when, here in the northern hemisphere, the light starts to return. Snowdrops appear. There is the promise of spring, of warmer days ahead. And yet February is also a tough month. Just when it is getting lighter, and your body angles towards being outdoors again, so the weather is strange, and unpredictable. Cold. February is often the coldest month, something that always takes me by surprise.

It is this month too when I start to think about swimming again. As much as I love the water, I tend to stay landlocked during the winter. I cannot face the drop in core body temperature, no matter how high the endorphin rush. The idea of stripping to a swimsuit when the air is icy, is beyond me. Even indoor swimming holds little appeal, that shiver sheer slipperiness as you dash from the warm water to the cold, murky changing rooms. And yet…. and yet… I find myself dreaming of pools, and lakes, the sea, a pond…

We all meet at St Pancras station. Jen and I have flown in on an extremely early flight from Copenhagen. Louisa joins us there, hungover from a payday night out. We go into M&S and do one of those food shops you can only achieve on the trifecta of: hungry, tired, hungover. We buy far more food than we need or could possibly eat today. It doesn’t matter. None of us is capable of making a proper decision at this point anyway. Outside, we find the bus. It is already hot, one of the last warm Saturdays in August, and the pull of cold water is like a hook, keeping us going through our fatigue. At the entrance to the ponds we scrabble together our coins, feed them into the machine, take the paper tickets. It is quiet, green, lush. We are early but already other women are taking up space on the grass. We find a spot in partial shade and settle ourselves. I go and change, eager to slip into the water. This is only the second swim post knee surgery and technically not recommended but my longing for the water overrides everything.

We leave Louisa asleep on the blanket and walk around to the pond. Getting in takes bravery. The depth of the pond means the water remains cool throughout the year, and there is no gradual incline to acclimatise your body. It is a straight drop down the metal rungs into the dark green water. Other women are behind, impatient to submerge into the depths. The water is cold – cold enough to make you gasp as you take the plunge. Jen follows, practically shrieking from the icy needles that sing on our skin. We swim in a slow, extended circle around the pond. I do an awkward doggy paddle – breaststroke is not allowed until four months post surgery so I cannot risk it, and crawl is only good when feeling anti-social or training. This is not the space for that kind of swimming. We talk as we swim, saying hello to other swimmers as we go by. At the far end of the lake is a rope, protecting the ducks and nesting moorhens. We hang onto the buoys, watching the birds go about their ducking and diving, foraging in the shallows. Then we turn and swim back.

I plunge my head underwater and the world turns a golden yellow-green, sunlight streaming through the water. Below everything is dark and my imagination delights in thinking of the scary creatures that must be swimming around and below me. Being in the water is bliss: the feel of cold on my goose-pimpled flesh, the suspension of gravity as I float on my back, staring blankly at the sky, watching the occasional cloud pass overhead. I love this pond. Other swimmers are relaxed, swimming in slow circles, hanging onto the ropes or buoys to catch their breath or talk more. The water is fantastically free of fast, aggressive swimmers. No triathletes overtaking at the next curve. This is pure pleasure swimming and it is delightful.

Afterwards I warm up in the sunshine. The grass is very full now – groups of women celebrating the sunny day. Nymphs live here, I think, as we pack up our picnic and head back to the bustle of the station, and our train north.