Boaties are being urged to exercise caution, especially in South Canterbury where many rivers remain swollen by recent flooding.
Footage of a jet boat mounting the land has sparked concern, its driver unsuccessfully navigated a swollen river as the person filming runs for cover.
"They shouldn't be doing it and I thought it was quite an idiotic, stupid thing to do," Navigation Safety Officer Gary Manch told Newshub.
"The rivers in flood, they're coming towards a weir - which is a big concrete non-bendable barrier - it was just a recipe for disaster."
The first driver managed to successfully cross a tricky section of the Ohau River in South Canterbury - but the second driver was not so lucky.
He's now come to the attention of the regional harbourmaster.
"Some people see it as a challenge but they don't make a considered risk assessment until it goes pear-shaped," Manch said.
Earlier this month, a boatie was captured going for a spin on a flooded Wanaka road.
It's this kind of behaviour that can lead to serious consequences.
Maritime New Zealand rules state that boats being driven within 200 metres of the shoreline must not be driven faster than five knots - roughly equivalent to the same speed as a brisk walking pace.
"We're not the anti-fun police but rules are there to make people safe on the waterway," Manch said.
