The maritime police say two incidents involving dive boats off Wellington's South Coast on Sunday morning could have ended in tragedy.
A boat dropping off divers capsized, stranding its occupants 100 metres from shore.
A second boat then issued a may day call after smashing its motor on rocks.
A diver had been swept away and was picked up by the police launch about 500 metres away.
The head of the police maritime unit,Sergeant Dave Houston, says the south coast is notorious for its strong currents and big seas and the forecast was for 20 knot northerlies, which is marginal for boating.
He says the diver who was picked up from the water was treated by paramedics.