It was "pure stupidity" that seven people and a baby were not wearing lifejackets onboard a boat on Lake Benmore in Central Otago, a maritime officials says.
Canterbury navigation safety officer Gary Manch said an enforcement officer found the only person wearing a lifejacket on the 5.3 meter long vessel was the skipper, a man in his 20s, despite the fact there were more on board.
Not putting a lifejacket on a six-month-old baby, who a woman on the boat was holding, was a case of pure stupidity, he said.
"Should an accident occur, the chances of the person holding onto the baby if the vessel capsized is remote, and once in the water with neither person wearing a lifejacket survival would be remote."
It was concerning people in charge of vessels did not think of the consequences of their actions," Mr Manch said.
"Nobody is faster than disaster."
Anyone on a boat that was six metres long or less in the region must wear a lifejacket, he said.
Enforcement action was being considered against the skipper.
Eight different councils, including the Canterbury Regional Council, will be trialling five "no excuses" days at different times this summer.
On these days boaties caught speeding or without lifejackets could face a fine of up to $300.