It was another very windy day, so perhaps the terns were looking for shelter in the harbor?
There were at least 21 terns. Here are a couple of photos showing most of the flock:
Many of the terns appeared to close their eyes as soon as they landed. In the images below, note the white spot at the lower edge of the black ear/eye patch. When the terns' eyes are open, their dark eyes blend in with the black ear/eye patch. But when their eyes are closed, the white lower lid comes up and contrasts with the black eye/ear patch. This had the interesting effect of making the birds look awake when their eyes were closed — i.e., from a distance, it looks like the terns have white eyes. [Click on the pictures for larger versions.]
One more close-up:
Nice to see some terns today!