Leon Reinbrecht has been charged with one count each of criminal negligence causing bodily harm and criminal negligence causing the death of Ken Brown.
The crash occurred on Shuswap Lake on the night of July 3, 2010, following a fireworks display.
The trial has so far heard conflicting evidence about whether the houseboat, piloted by Brown, was lit.
On Wednesday, Darren Schneider said by video from San Diego and that both boats were lit before they collided.
Schneider, whose family has a cabin on the lake, said he had just returned to shore after watching the fireworks when a boat caught his attention.
“I heard the sound of an engine on a boat going fairly loud, so I turned to see what was going on,” he testified.
“It sounded like it was going a little fast for the conditions and that time of night. I see the speedboat travelling east to west and the houseboat travelling fairly slow headed east. As I watched, I said to myself, ‘I hope that speedboat is out further than I think.’ It looked like they were on a collision course.”
Schneider said white lights lit up the cabin of the houseboat.
"I could see both boats did have lights on. I was concerned when I looked at it that they were on a collision course. They were on the same course.
“That’s when you could see the lights come together and that’s when the collision happened and you could hear the thud as the two boats came together.”
Schneider said the crash happened about five seconds after he first saw the speedboat.
He said he ran back to his cabin and asked family members to call 911 before boarding a paddle boat to help those involved in the crash.
“The people on the houseboat were calling for help,” Schneider said.
“You could hear exactly what they were saying. They were yelling for someone to please come help them.”
Multiple witnesses have told the trial that a speedboat was being driven erratically prior to the crash.
Last week, a woman who was aboard the speedboat testified Reinbrecht had been drinking and smoking marijuana. (Kamloops This Week)