Strange waves are making beach visitors in San Diego do a double take.
The ocean swells appear to be glowing.
A rare red tide caused by algae has been illuminating the waves at night, turning them into a neon show.
It's caused by a chemical reaction on the cellular level, Scripps Institution of Oceanography Professor Peter J. Franks told the latimes.com . He calls the phytoplankton "my favorite dinoflagellate."