Leah Smith testified in court on Wednesday that she remembered serving Linda O'Leary three-quarters of an ounce of vodka with Perrier sparkling water at a dinner party she hosted the night of the fatal boat crash on Aug. 24, 2019.

Smith told court O'Leary said, "If you're making a beverage for me, you need to make it super light because I'm the DD."

The witness testified she didn't know if O'Leary drank the beverage but added she remembered seeing the glass turned upside down and assumed she had water with her meal.

The dinner party ended around 11:30 p.m. From that time, the court watched surveillance video from the Smith's dock, which showed Linda O'Leary driving off with her husband and friend Allison Whiteside.

OPP Detective Const. Sean Richardson took the witness stand and described trying to reconstruct the crash with his team of investigators.

He said he went out in a boat with Dr. Irv Edwards, the other boat owner involved in the crash, who estimated for police where his boat was in relation to the O'Leary's.

Richardson said he couldn't determine how fast the O'Leary boat was travelling but guestimated the O'Leary boat had been going between 24 and 30mph.

The defence questioned the officer's estimates, suggesting the O'Leary's boat may have been moving below 20mph, and Richardson agreed it was possible.

CRASH KILLS TWO PEOPLE

O'Leary faces one charge of careless operation of a vessel under the Canada Shipping Act. She has pleaded not guilty.

Linda was captaining the boat, and her businessman husband, Kevin O'Leary, was onboard with one of their friends when the boat struck another on Lake Joseph.

The collision claimed the lives of 64-year-old Gary Poltash of Florida and 48-year-old mother Suzana Brito of Uxbridge.

Nearly two hours after the deadly crash, O'Leary provided a breath sample to police, which a provincial police officer testified on Monday registered an "alert range" blood alcohol level. The officer said O'Leary told her that was because she asked someone for a drink after the collision.

The driver of the other vessel, who took over from Edwards not long after leaving shore, was charged and convicted for failing to display the stern lights.

The trial resumes Thursday with more testimony from OPP officers with the forensic investigations team.

With files from The Canadian Press