Boaties are being urged to make sure they have the right equipment after an inflatable with three men on board was swept out to sea.
Police say the Palmerston North men went on a diving trip on Saturday from Akitio Beach, 85 kilometres southeast of Dannevirke.
The motor on the boat seized while they were diving and the boat went adrift.
Inspector David White said they had no anchor, life jackets, safety beacon, radio or cellphone and were lucky another man on shore was able to raise the alarm.
It took a helicopter and local fishing boats half an hour to find the trio, by which time they'd been swept five kilometres out to sea by strong winds.
Mr White said going to sea without the proper equipment is sheer stupidity and boaties need to be more responsible.