Wellington - Searchers called in a New Zealand air force plane with sophisticated night vision equipment late on Monday to look for a small boat with five people aboard missing at sea.

The skipper of the 5.5-metre boat, which had two adults and three children on a snorkelling trip off the Bay of Plenty, on the east coast of the North Island, reportedly sent a text message to his wife early in the afternoon saying they were lost.

A search by coast guard boats, a helicopter and fixed wing aircraft was curtailed because of high winds, heavy rain, rough seas and poor visibility in the area of a wildlife sanctuary, 14 kilometres off the small settlement of Maketu, where they had headed.

News reports said that two adults and three children aged 12, 13 and 14 were on the missing boat, which had a marine radio, but searchers were unable to contact it.

There was no news of the boat more than nine hours after the text message was sent and police sergeant Craig Madden, of Tauranga, said that although the boat's occupants were known to have life jackets concern was mounting for their safety. dpa