St Catherine's Island, Tenby, Pembrokeshire

Big tide and high winds, so down to Castle Beach in the hope of hefty waves and perhaps a blip of the local youth throwing themselves about in the sea. Sure enough, a group of teenagers arrive and charge into the spray.

All of a sudden I'm aware of somebody else there with a camera. While I hang back a bit from the lads in the sea, this older fella is more energetic, getting closer to them, dancing around the beach. I recognise him. It's Martin Parr.

We're only a couple of metres apart at times. What should I say? Nothing for now, he's busy.

The man who runs the beach cafe asks if we can tag him on Instagram if we get any decent pictures of the waves. "Your cameras will probably do a better job than my phone," he says cheerfully.

Martin Parr looks sheepish. I want to tell the cafe guy he's talking to a photography legend, so yes, Martin Parr is likely to get some better shots than him. But that would embarrass the cafe guy and maybe Martin Parr, too, so I just nod. And the three of us go back to our thing.

Then Martin Parr starts shuffling away. I watch him go up the slope at the back of the beach, over the brow and on to Bridge Street. I stay where I am and flick through the handful of shots I've taken since spotting him 10 minutes ago. They're all rubbish.