A fire on a boat in the Fraser River sent three people diving into the water near the Musqueam reserve Sunday afternoon, and fire crews say they were fortunate not to sustain serious injuries. (CTV)

A fire on a boat in the Fraser River sent three people diving into the water near the Musqueam reserve Sunday afternoon, and fire crews say they were fortunate not to sustain serious injuries.

Vancouver Fire Rescue Services assistant chief Ken Gemmill told CTV News Vancouver the 20-foot vessel's motor caught fire while its occupants were taking it out for a test drive in the river.

Vancouver police said in a news release that the fire started near the boat's fuel tank, which had recently been replaced. Police described the incident as an "explosion" caused by the fire's proximity to the fuel tank.

Police said the explosion occurred around 3 p.m., shortly after the three people - two men in their 40s and a teenager - had launched the vessel.

The trio avoided serious injury by jumping overboard and holding onto the side of the boat while guiding it to shore, according to police.

Gemmill said the situation could have gotten worse.

“If they would have been stuck on that boat, it might have gotten a little ugly," he said. "The current’s going pretty good right now. It looked like it happened pretty close to shore, thankfully.”

Vancouver fire and police boats responded to the scene, and firefighters sent a ground crew to put out the blaze as well, Gemmill said.

None of the three people on the boat was seriously injured, though one person was treated for mild cold exposure, according to Gemmill.

After extinguishing the boat fire, crews towed it to shore to begin an investigation into what caused it to erupt in flames.