There is a tide in the affairs of men

In the Spring edition of Visi magazine I wrote an essay declaring my intention to swim in the sea every day from 1 September 2013 till 1 September next year.

It seemed like a good idea when I wrote it, even though that was the middle of a Cape storm, when barnacles were repenting their vagabond ways and even mussels were staying in their beds. There were still several weeks before 1 September, and if something is far enough in the future I'm always confident I'll succeed. I can do anything, so long as I don't have to do it right now.

Last Sunday was 1 September and it came after three days of rain, and two days after the snow. You couldn't see the snow but under the right conditions you could feel it. The right conditions for feeling snow are standing in your swimming trunks on the shingly beach at Rocklands, just off the Sea Point promenade, in a grey wind under cold grey skies. Later that afternoon the clouds would pass and sunlight would come out on blue water, but I had no way of knowing that then.

I didn't really swim: I dipped my body like a toe. I am not afraid of the cold, but this was a puckered misery of seaweed and black rocks. The coldness was mainly in my head but it came out in my flesh. An old couple walking their dog stopped to stare at me, shivering on the shingle like a fat Na'vi or an uncute smurf.

Next day skies were clear and the sun shone, but four days of storm had churned up silt and broken kelp and the shoreside water was the colour of soupy rust. The longer I looked at it, the farther away it felt. I couldn't go in.

I walked back to my home thinking about everything I've started and not finished. I thought about the books and scripts, the pilot I was asked to write for an American drama series, the love affairs and gym plans. I thought about how my best years have passed unused because I lack some essential quality of stamina, and now it's late ever to be better. I might have cried, but it seemed too much of a commitment.

Then I read about Diana Nyad. In Greek mythology a naiad is a freshwater nymph so technically she should be Diana Nereid, but nominative determinism is not a precise science. On Monday she arrived on a beach at Key West, Florida. She had been swimming for 53 hours. She covered 180 kilometres horizontally and probably the same again vertically as she rose and fell with the chop. There are sharks and jellyfish and currents, and the warm water dehydrates you then the cold takes your strength. She swam through two long nights above kilometres of black toothy water, below kilometres of black empty sky. On the last night she saw the lights of Florida and only then did she believe she'd make it. She still had fifteen hours to swim. Diana Nyad is the first human being to swim unaided by fins or shark cage from Cuba to Key West, and she is 64 years old.

After she came from the sea in her blue bathing suit and swimming cap, she staggered stunned like a woman from a smoking building. She had swallowed litres of seawater and had been vomiting through the fifty-three hours. "I didn't realise," she said, "how much suffering there would be."

This was the fifth time Diana Nyad had tried to swim from Havana to Florida. The first time was in 1978 when she was a kid of 29 and it took 32 years before she tried again. Each time she was beaten by currents and swell and asthma and deadly box-jellyfish that stung her through her protective gear. Each time she realised how little she understood the job. Each time she came back.

Diana Nyad doesn't have romantic ideas about the ocean. When you're swimming across it, she said, the sea is a brutal foe. It's like life: the only meaning is to keep going, and the only victory is touching the other side. In her interviews this week she spoke a lot about life and the concentration of age, the importance of perspective to understand what you're doing and why it matters. She had more energy when she was younger, but she didn't have age. She succeeded this week because the Gulf Stream was in her favour, but also because she was finally old enough to succeed.

I finished reading about Diana Nyad. It was still the second day of spring. I took my towel and walked back down to Rocklands. I may not be old enough just yet, but I can start getting ready.