Spring tides and slightly warmer waters have brought a little zing to coastal sea swimming.

Kim and I had a Sunday night swim and she returned to the beach with the sensation of a stinging nettle encounter on one arm, neither of us had seen any jellyfish but that seemed the most likely cause of her discomfort.

Yesterday I was working in The Box and was having a natter with a colleague. We were talking about our weekends and were surprised to realise that while I was in the water on Sunday she was basking, like a reptile in the sun, on a boat moored not far from where Kim and I were swimming.

We were not even in the Natural History department when she flashed me the picture of the Compass Jelly Fish she had seen on her return to land. The Sunday mystery sensation explained…