Sometimes something is such a habit that you almost cease to realise its presence or utility. Such is the case with the wristwatch.

I was at the Guillamene, there by myself as more usual these days, when I realised that I wasn’t wearing my watch. The last time I’d swum open water without a watch was when we’d had to remove it for the five-hour Torture Swim on the penultimate day of the 2009 Distance Week. I recall that day that I found that really disconcerting, as it was intended to be. And I wasn’t the only one, most of us wear watches when swimming open water, (even those who don’t wear them pool training).

Even during my E.C. solo, (contrary to what I was advised), I wore a watch, though I didn’t look at it until I was stuck fighting the tide outside Calais.

But at the Guillamene, the air temperature had dropped significantly overnight. The water was calm with just some small swells, and the sky was blue but there was a chilly wind. Summer was definitely well and truly over and we were jumping right into early winter.

My plan had been a swim to the beach and back, my most common swim at the moment. But without a watch I realised suddenly how much I relied on it.

For unaccompanied open water swimming, my most usual swimming, I use my watch constantly, to monitor my speed and progress.

The most obvious use is to check arrival at spots where I know my time window should be, for example getting to the beach should take me 30 to 35 minutes (condition and training dependent). The actual time isn’t important but what is, is any significant deviation from the normal time window for swimming a known distance. This will tell me if there is an unusual current in operation. Getting there very quickly but unexpectedly, will warn me I’ll have an adverse current on the return.

Another potential use is if I feel I am getting cold, that I can fit this information into my experience and adjust the time I plan to swim accordingly. This happened last Sunday in fact, when I took two people who didn’t know the area, but strong swimmers, out to Newtown Head and the caves. I was in skin, they in wetsuits, and while I slowly circled and swam and we floated around outside, I was getting chilly. By 30 minutes I knew I had to go back to my normal pace or pay the price. Without my watch even a ten minute delay would have seen me get colder, whereas I knew if I started swimming harder by 35 minutes, i would not get too cold.

Or even if I find I am getting cold when I don’t expect to, a check on elapsed time will tell me if I should be worried or careful and cut my swim short.

The day without my watch was fine, the conditions were good, and in fact the time passed more quickly than usual. But I wish I’d had my watch with me. For safety.