Routine activities pop back into my life as little chunks of euphoria.

I especially love Sunday Morning Sea-Worship which I have been doing for a few years with ML, M & R – family by blood and choice. There have been times when we couldn’t all get in the water – what with broken spines and hips. Operations. Illness. Disability. Bereavement. But today we are back to our fabulous foursomeness.

We meet 9.30am at the November-chilled beach peopled with dog walkers and others groups of swimmers. The wind bites but the sky mirrors the zingy cobalt costume that M & R bought me for my sixtieth. I am not resorting to wetsuit yet. ML and R have made it through two winters without. I shall see how long I can hold out.

Low tide. My favourite because all you see is horizon; and no one can hear the daft songs I make up to lure myself into the water. We giggle and banter, picking our way over stones and silty sand, through tangled black seaweed, to the water’s edge.

Once there, we each have our own process. R dives straight under the waves like a dolphin. ML and M both pace forward with steady determination, but in the act of submerging M lets out a full-throated yell, whilst ML only gasps and smiles.

Behind them I am testing the water with my feet, then legs. My belly gets brave and then it’s Owwwww as icy water meets backless swimsuit. Exhale, exhale, exhale. I sing my made up tunes “cold water is good for me.’ The others tease my hesitation. “Get your shoulders under!” “Shut up, I’m doing it,” I’ll shout back, mock-cross.

Come on Rachel, it’s time. I brace. I start counting 1, 2 and trick myself by crouching suddenly under before reaching 3. I catch my breath as the waves catch my body. I join the others. Enveloped. We scream and squeal, squeal and scream. We’re alive.

That moment of immersion is the point. The conscious act of will it takes to exit right out of comfort and plunge into discomfort. Knowing that it will be hard but okay. More than okay. Feel brilliant after. I try to carry that moment with me through the week, summon it when there are things I can’t or don’t do. Of which there are many.

It’s choppy today. I love the way it distracts you from the cold, makes you playful. Here we are, jumping and frolicking in the white foam. Avoiding waves becomes catching waves. Under them, over them, in them. I realise how absurd it would be to try and control them. We are best when we are part of nature – elemental.

The sky has split – the left half is still blue with a creamy white disc of a sun but the right has darkened to an ominous shade of slaty black. I swim eastwards as if I can capture the sun and keep it over me. But the two halves soon join in darkness and big droplets of rain fall onto our heads. We laugh. This is absurd and brilliant.

Endorphin-fuelled, we dash to the big yellow tubs we left by the shore, rescue our towels and robes and scamper back up the beach to our cars, where the process of drying and dressing has become an art form. Sometimes our favourite local dog, an old girl, shaggy and white, waddles over and sits on our feet for damp cuddles.

We drive to the coffee van at the shingle beach around the corner. Something magnificent has happened. We all spot it, signalling each other from our cars. The split sky, the simultaneous rain and sun, has caused a most audacious rainbow, a huge arc of seven intense colours reaching right across the sky and above our heads.