He had spoken to the boat's owner who said the fire started as he revved the motor and it was probably caused by an electrical fault.
"The guy just jumped ship," he said. Oliver didn't know who the two people in the speedboat were, he said, "just good sorts in a boat".
Dave Black, the deputy harbour master for lakes Wanaka, Wakatipu and Hawea, said he had adopted the same tactic when a boat caught fire on Lake Wakatipu seven or eight years ago.
"We turned the boat one way and squirted water on to the fire quite easily, and we did have a fire crew on board as well," he said.
"I wouldn't call it a legitimate tactic but if it puts the fire out, then so be it. As long as everyone gets out safe I don't have a problem with it."
Fire Service southern communications centre shift manager Riwai Grace thought it was "ingenious".
"They didn't put themselves in any danger so, you know, I think it was just someone displaying good old Kiwi ingenuity.
"That's the sort of thing that shows New Zealanders have a bit of ticker, so I thought it was quite cool."
As of yesterday afternoon, the video had been watched more than 50,000 times on YouTube and 70,000 times on LiveLeak, and attracted hundreds of comments.
"That guy is David Hasselhoff from Baywatch," said tuubeyube on YouTube.
"Why risk a second boat disaster and possible injury to splash water on a boat that's clearly totalled already and in danger of damaging nothing around it?" darthmullet1 said on LiveLeak.
Oliver said the video had gone "mass viral" and he'd had dozens of calls about it.
"People are trying to contact us like crazy. Even CNN wants to talk to me. It's a bit different, eh."
