Six degrees of separation is the idea that all people are six, or fewer, social connections away from each other. When, last week, I met a man who’s wife was a cousin of Donald Trump, I knew, because of six degrees of separation, that because I knew the man and he knew his wife (presumably, unless they’d stopped talking!) and she knew Donald Trump then I also knew Donald Trump.

This six degrees of separation connects the entire world to everyone else, which is nice as it shows that we’re all connected. Though Donald Trump would claim not to know me. Or the man. Or his cousin. And it would all be FAKE NEWS!

Six degrees of separation also means something else. It’s just six degrees which separates a Scotsman from his wetsuit because, this week, Challenge Roth posted an apology/warning. Watch out, they said, the water in the swim leg is only 16 degrees – it’s going to be a cold, cold swim!

Unless you’re Scottish – and the water temperature’s currently 10 degrees – in which case 16 degrees sounds like a warm bath. Or at least a warm bath that you’ve been sitting in for an hour and it’s starting to turn cold.

In order to test this theory that the swim would be pleasant, this week I decided to go without a wetsuit and swim in just my trunks.

I was in London for a few days and had spotted that you could swim outdoors in the Serpentine in Hyde Park. Whenever I go to London I always like to try something new. This time I tried modern opera* and swimming in the Serpetine.

First, I had to buy a towel. As I was swimming after I’d checked out of my hotel, I had to find a towel to dry myself. As the Serpentine is in Knightsbridge, and I’d forgotten to buy a towel from a cheap shop before heading over, it looked like I was faced with either buying a monographed gold set from Harrods or the finest designer ostrich feather towel from Harvey Nicholls. Luckily I spotted a Laura Ashley with 50% off sign and managed to get one there. Even that though was a struggle.

“I’d like to buy a towel, please,” I said to the assistant

“What kind of towel are you looking for,” they asked.

“The cheapest!” I said

They gave me a look which said “Knightsbridge is not for you, sir!”

The Serpentine Lido is an old white building with a marked 30 metre by 100 metre bay at the edge of the Serpentine lake. While the changing rooms were small – only two changing booths – the Lido was clean and the staff pleasant.

It was raining, and a Monday morning, so that probably explains why I was the only one there. Although three women in wetsuits left as I arrived, that was a coincidence – they’d already left the water when I got there! They said “You’re brave” as they saw me in my trunks. I assume they meant for swimming in the cold water and not wearing trunks when over 40.

The water was bracing but, after swimming in 10 degrees for the last few weeks, it was almost, but not quite, a warm-ish. Either way, nothing to complain about for Challenge Roth itself.

With no one else in the pond, I had the Serpentine to myself. Except for a few swans. And the lifeguard who clearly thought he was going to get to go back inside when the women got out of the water and was annoyed he had to stay when I came in. But knowing there was someone watching was reassuring in case the Swans decided to attack.

If you’re in London I’d recommend a trip to the Lido. It was fun to swim in the middle of Hyde Park and, with the pool to myself, it was quite a change from the crowds around Harrods.

*P.s. I cannot recommend modern opera. The singing was good and I got caught up a few times in the music, but the lyrics were awful. Or at least the lyrics as translated and projected above the stage as surtitles.

At one point, the hero, a man in love with a woman, spent 10 minutes singing about “the oxen in the field are looking strong”, “tonight’s a good night to pick strawberries” and “this is not the time for my plough to break” while the woman he was in love with repeatedly sand “I’m not as black as you think I am – it’s just the light!”.

Farming and mild racism.

That’s modern opera.

It wasn’t for me.