The 34-year-old man who went missing off Northland's Uretiti Beach yesterday is presumed to have drowned.
Alexy Ivanov of Auckland was last seen entering the water about 5pm.
Department of Conservation staff at a campground alerted police after they noticed his clothing and car had not been touched an hour later.
A search of the area lasted until dark yesterday and continued this morning, including a helicopter covering the area around where Mr Ivanov went missing.
Algae bloom made visibility difficult, said police.
Police are also searching the beach on quad bikes and in a 4WD vehicle.