"I hooked the 4WD on to it and pulled it out of the shed," he said. "I was going to lose the boat and the shed and the [house] bus."
He had extinguished most of the fire with a garden hose by the time the fire brigade arrived.
The fire had been caused by a welding spark, he said.
Mr Robertson, a keen fisherman, built the boat about 25 years ago.
He said the boat was "buggered" and most of the equipment inside it burnt.
The house bus had superficial damage.
Carterton fire chief Wayne Robinson said it was lucky Mr Robertson heard the tyre explode, "or else it would have been a totally different story".