I swam with seals and puffins off the south-west coast of Wales

In Britain it’s always worth hanging around to see what the weather will do. In the case of the islands off the Pembrokeshire Coast national park, I’ve been hanging around, off and on, for more than three decades, going back repeatedly to the Marloes peninsula in the hope of catching the right wind and waves to visit the rocky islets of Skomer, Skokholm and Grassholm. Sometimes the boat was fully booked; more often the service was cancelled due to wind, swells or storms. But this time, finally, it looked hopeful.