TORONTO — From script to sea, there are many Canadian connections to new Second World War drama “Greyhound.”

Gordon Laco of Midland, Ont., was the film’s naval consultant and incorporated several homegrown elements into the story, which stars Tom Hanks and is set in winter 1942 during the Battle of the Atlantic.

“Canada, at the end of the war, had the third-largest Navy in the world — and the Battle of the Atlantic is a big thing for us,” the retired officer of the Royal Canadian Navy said in a phone interview.

Hanks wrote Apple TV Plus’s “Greyhound,” in which he plays a U.S. Navy officer leading the destroyer Keeling (code-named Greyhound) — as well as a Canadian escort ship and two others — across dangerous Atlantic waters. Their mission is to protect a convoy of 37 merchant vessels bound for England.

The two-time Oscar-winning actor based the screenplay on C.S. Forester’s novel “The Good Shepherd.” Aaron Schneider directed.

Laco, who has been a technical adviser/historical consultant on more than 60 productions, said he was recruited for the film by Canadian executive producer David Coatsworth. The two have also worked together on the TV series “American Gods” and the made-for-TV film “The Crossing.”

To depict the fictitious Canadian escort ship HMCS Dodge (code-named Dickie), Laco got the team to do an electronic scan of the warship HMCS Sackville in Halifax and use the dimensions.

Laco gave Dodge the pennant number K136 as a salute to the real HMCS Shawinigan, which sank with its entire crew after being torpedoed by the enemy a few kilometres off Channel-Port aux Basques, N.L., in November 1944.

Laco also got the crew to film scenery shots aboard HMCS Montreal for a week at sea in January 2018, to help depict the dramatic winter waves and sky of the North Atlantic in the story.

CGI crews digitally added ships from the story into that footage.

“In the film, whenever you see a bow wave or a wake or a ship turning, that’s the computer-generated ship in the film with HMCS Montreal’s wakes under her,” Laco said.

In advising on the battle scenes, Laco was inspired by close-up, real-life fights between Canadian ships and submarines — HMCS Assiniboine vs U-210, HMCS Chilliwack vs U-744, and HMCS Oakville vs U-94.

To highlight “the fighting spirit of the Canadians,” he inserted a line said by an American sailor into the script: “Go get ’em, Dickie!”

“The close, savage action we showed in the film really happened, and it was really done by Canadian warships,” he said.

Laco also suggested the script have “passive sonar,” which involves an operator listening for noises of nearby vessels.

“It occurred to me that Forester had left that out of the story because the book was published so soon after the war and he didn’t want to give the whole game away about how effective anti-submarine warfare is conducted,” he said.

“So working with the director, we wrote in another line of dialogue…. lines like, ‘I hear slow screws turning, 60 RPM.'”

Laco also drew charts for the movements of the ships, trained actors on how to use the sonar set, and told them which direction to look so their sight lines would be accurate for the vessels on the horizon.

Filming took place on a museum ship in Baton Rouge, La.

Laco said Hanks “has an immense reverence for history” and “is everything that he seems to be.”

“He’s a patrician gentlemen, with regards to politeness. He works very hard. He’s always prepared.”

Laco brought to the set a navigation instrument that once belonged to one of his late neighbours, who participated in a fight involving HMCS Assiniboine during the Battle of the Atlantic. He gave it to Hanks, who showed a great reverence for it.

“Hanks put it on the chart table, and you see that little round brass navigation device in every scene where you get a glimpse of the chart cable,” Laco said.

“He understood what I was telling him — that there are people’s experiences to be honoured, as well as an entertaining story to be told.”

Other productions Laco has worked on include “Master and Commander: The Far Side of the World,” starring Russell Crowe and directed by Peter Weir.

He said his job is to help the director tell a story in a way that’s technically and historically accurate but also compelling. He has to develop close relationships with many departments on a production so they understand he’s not trying to embarrass them if he tells them they’re depicting something inaccurately.

“That’s terrible power,” Laco says with a chuckle.

“I could create mayhem or confusion if I said things irresponsibly or without thinking about them first. On the other hand, I can do a lot of good.”

This report by The Canadian Press was first published July 22, 2020.

Victoria Ahearn, The Canadian Press