Once the kids had (briefly) exhausted themselves I would do a bit of snorkelling. I sorted out the "sun burn on the head" issue by using a very thin hood - normally warm under a wet suit in very cold water. It may look a bit over the top - but it seems to work well!
One of the things I like about snorkelling is the ability to be in that transition zone between water and air - and in this zone the light is refracted and reflected in many different ways.
These images were taken with a little waterproof point and shot, held out in front of me and angled a little up at the sky. I rather like the results.
You can find more sky shots (and less terms you last heard in Year 9 Physics!) at Sky Watch Friday.