A mile in the Lido this morning, an early autumn swim. The temperature has dropped enough to bring shivers when I first get in,  and the first length is one of acclimatising to the temperature. After that there are 5 lengths of pure bliss, my skin glowing against water which feels the perfect temperature. Then the chill sets in and with it comes the real joy of this swim; the challenge of incipient cold and the awareness of my body mastering it.

The water is blue and silver and jade, silver at the surface which looks from beneath like a length of silk laid over the pool. Looked at from underwater, the far end of the Lido looks deep blue, the deeper water shading to azure. The bottom is blue and jade depending on whether the algae has been cleaned. Both are beautiful. The first leaves of autumn litter the water, floating on the surface like tiny hands or hanging beneath the surface. The most striking are those which litter the pool bottom like candied rose petals scattered across a cake.

Despite my chill I can easily make a mile standing shivering under the showers later full of a sense of achievement. This may be my last non-wetsuit mile of this year. By the time the sauna opens, which makes warming up easier, the water temperature will have dropped too much to allow a mile without a wetsuit. No matter. Welcome, dropping temperatures. Welcome, gods of the turning year. Winter swimming. Bring it on.