Photo by Chris Garden.
The image was captured by Dunedin freelance photographer Chris Garden, as he drove around the coast on Wednesday "looking for some good waves".
When he stopped at Karitane, he noticed several people surfing among the foam, which was being churned up by the swollen Waikouaiti River.
"As if surfing in winter around Dunedin wasn't hard enough with the cold, you add in foam and trees floating out of the Waikouaiti River," he joked.
The foam is created by algae and ocean impurities, which may include salts, dead plants, decomposed fish and seaweed excretions.
