Surf Lifesaving New Zealand says some Auckland beaches, such as the bay where a teenage boy got swept out to sea, are too dangerous to swim at if they are not patrolled.
The search continued on Saturday for the 15-year-old boy missing since Thursday after being caught in a rip at O'Neill Bay, near Bethells Beach.
Bethells Beach patrol captain Chase Cahalane says the teenager got into difficulty at the southern end of the bay, which has a notorious rip.
Warning signs advise people against swimming at the unpatrolled bay, which is in a secluded area with access by foot over towering sand dunes.
Surf Lifesaving says swimmers have drowned at O'Neill Bay, and although it is no more dangerous than any other West Coast beach - such as Piha and Muriwai - it has limited cell phone reception and it is therefore difficult to call for help.
Water Safety New Zealand says there have been 14 drownings in New Zealand this year - three of which were of people caused by rips.