Yesterday I looked at the horizon and saw Farallon Islands gently hanging at the sky and well above the ocean. Nearby two ships were floating even higher over the sky. I sent the image to Dr. Andrew Young. Dr Young explained to me that there are few phenomena involved. He wrote:
"This is probably looming (and mirage) of the sea surface beyond the apparent horizon.
The sea surface seems to be unusually calm; perhaps the wind was blowing
offshore, and damping the incoming swells? So the sky reflected in
the middle distance is not far above the sea horizon. But the sea *at*
the horizon is dark (meaning the waves are steeper there).
That lighter strip of sea gives the impression of being a miraged zone,
because it matches the sky so well."