Before I went out to Sponge Bay this morning, I was reading an article in The Pastel Journal written by Richard McKinley about plein air painting - a field guide. He suggested doing three thumbnails before beginning sketching - the first a composition, the second an exploration of tones, and the third a notan sketch. I hadn't tried a notan sketch before, so thought I might do this. Notan is a Japanese word which means "value as design". A notan sketch is done in black and white only which helps you see your composition as an abstract. Tones lighter than the mid-point are left white, and tones darker done in black.
Here is a photo of the bay this morning, looking towards Tuamotu Island and beyond it Young Nick's Head:

I decided to bring my focus in to the bottom of the near cliff and try to capture the waves. Here are the thumbnails I did this morning. I didn't have a black pencil, so used dark blue for the notan thumbnail.

Richard McKinley also suggested beginning the sketch itself with blocks of broad colours which you smear into the page. This forms an underpainting. The idea is to then add details and highlights. I tried this, but didn't like it very much - for one thing the underpainting covered the paper, and I like to leave some showing. It was also a bit messy! I had pastel all over my hands. It didn't matter, of course, because it was such a joy just being there.

There was a strong north-westerly wind making flying icing-sugar of the foam of the breakers.

My friend and I sat and had our hot drinks together, warming up in the car, out of the wind. We watched the shadows of the clouds race across the bay. She said to me "how on earth are we supposed to capture that?!"