The little boat looked so frail and was clearly as light as a feather. But when Kit lifted it into the water and jumped in, fitted the oars into the rowlocks and began rowing around on the lake, it seemed to work beautifully. I remembered reading in a history book about round boats that early man used, called coracles, made of sticks and animal skins. Robin was a modern version of a coracle, in a more boat-like shape.

‘She’s brilliant,’ he called. ‘Who wants a ride?’

Jimmy put his hand up. Kit came back and helped him climb in, instructing him to step carefully, only on the wooden base, and not on the canvas sections.

‘Don’t go too far,’ I shouted, praying that Jimmy wouldn’t try to stand up and capsize them. ‘Look after my brother, Kit.’

‘I will, don’t worry,’ he called. As they rowed way, with Kit singing, ‘Yo-ho-ho and a bottle of rum’, Jimmy waved back, his face a picture of delight, and I loved Kit all over again for his kindness.

‘Why don’t the rest of you go for a dip?’ Mr Waddington suggested. He was still clutching the champagne bottle and I’d spied him swigging from it, when no one was looking. ‘You can all swim, can’t you?’

The swimming platform had a ladder, so that you could climb gracefully into the water without having to jump in or wade through the reeds. There was even a little hut for changing in, not that the boys bothered. They simply changed there and then, and immediately leaped straight into the water and began shouting and larking about.

How can I describe the feeling of plunging into that lake for the first time? I was used to the turbulence of the sea, to leaping over waves or, on calmer days, floating on my back, enjoying the buoyancy of the salty water and watching the clouds. But I had never swum in fresh water before. I was immediately out of my depth and the cold made me gasp at first, but it was no worse than I’d known in the sea, and I was already warmed up by the time I’d swum a few yards.

The boys were still messing about, so I carried on swimming out into the lake until their voices receded and I could enjoy the relative peace. The water felt wonderfully silky on my skin and had a very slight, but not unpleasant, smell of vegetation. It was clear enough to see my feet, although it gave them a greeny-brown tinge. There was no weed in this area – presumably it was too deep to grow here. I wondered briefly about fish and other creepy-crawlies, but the sensation of being immersed in that cool, silky water was so delightful I put the idea from my mind and carried on.