VANCOUVER -- Karl Lilgert was either having sex or a heated argument with his former lover on the bridge of a B.C. ferry the night it hit an island sank, the prosecution alleged at the man's criminal negligence causing death trial Thursday.

Crown lawyer Michel Huot accused Lilgert of fabricating his evidence, saying he was distracted by his former lover -- the only other person on the bridge when the Queen of the North crashed -- setting off an evacuation where it's believed two passengers were left behind.

But Lilgert insisted under repeated questioning that he was paying attention and that he made course alterations to avoid Gil Island in March 2006.

The trial has already heard that Lilgert and Karen Briker had been working alone together for the first time since they broke off their relationship.

"The relationship the two of you shared, the attraction was powerful enough that whether it was sexual activity or an argument or a discussion coming out of the breakup of the relationship, that's what occupied your attention that night, not navigating the vessel," Huot said, ending his days-long cross-examination.

Lilgert simply replied, "No."

Huot earlier suggested that Lilgert knew Briker would be on the bridge that night so he cut his break short and relieved Second Officer Kevin Hilton early so he could be with Briker on the bridge.

"And when you got to the bridge, whatever happened between you, whether it was sexual, an argument, a heated discussion, you just weren't paying attention to navigating the vessel," Huot said.

"I'm suggesting that I was navigating and paying attention to the best of my ability," Lilgert responded.

The crash set off a frantic night-time rescue where boats from the nearby community of Hartley Bay and a coast guard vessel helped save 99 people from the Queen of the North. But there were 101 people aboard and Gerald Foisy and his common-law spouse Shirley Rosette haven't been seen since.

Lilgert told his trial earlier that he made two course alterations. The first came three minutes after Sainty Point at the end of Grenville Channel -- a key course change necessary in order to avoid Gil Island, while the second alteration was made to adjust for the effect the wind was having on the vessel's course, he said.

Lilgert testified that he decided to delay the scheduled alteration and guide the ferry closer to Gil Island because a tugboat towing a log boom and another vessel -- which the Crown has called "the phantom vessel" -- were in the area.

Electronic navigation evidence already presented to the court shows the ferry did not alter course after exiting Grenville Channel and crashed into Gil Island.

"The vessel travelled in a straight line without an alteration from Sainty Point to ... just before the island," Huot pointed out to Lilgert.

Lilgert said he does not understand why the electronic data didn't show the course alterations he said he made.

The Crown showed the jury maps that depicted the crash site and the route that the ferry would have travelled if no course alterations were made at Sainty Point.

The route lines up very closely with the point of impact, which the Crown said came from GPS data from an RCMP boat that attended the crash site.

"You hit this exact same impact point that you would have coming out of Sainty Point and never changed your course," Huot said.

"Of all the places," he continued, "that you could have hit all along the coast (of Gil Island)...you happen to hit the same spot, with all your manoeuvring, that you would have hit had you just never turned."

"I can't explain that. I'm sorry," Lilgert responded.

Huot went on to suggest that Lilgert, whom the Crown has described as an experienced mariner with over 24,000 hours at sea and 6,000 hours as an officer, would never have made the decisions he said he did.

The court previously heard about the standing orders on vessels like the Queen of the North as well as collision guidelines in the Canada Shipping Act.

Those guidelines specify certain actions that a navigator like Lilgert should have taken in the situation he was in.

The inclement weather, the other ships in the area, the course alterations, the trouble Lilgert said he was having with the radar, each one of these issues, Huot suggested, should have compelled Lilgert to call either the ship's Master or the Second Officer. But Lilgert said he did not.

Additionally, the court heard that the collision guidelines suggest reducing speed when travelling in low visibility, which Lilgert said he experienced that night.

"I'm going to suggest to you that you have concocted virtually everything that you have testified about from Sainty Point until the point that you see the trees at the very least," charged Huot. "It's a fabrication."

"I disagree with that," Lilgert responded.