Landry, 67, was charged in the death of Phillip Boudreau, a 43-year-old man from Petit-de-Grat who disappeared after a confrontation on the water in 2013.
Landry, who was found not guilty of second-degree murder, is scheduled to be sentenced on Jan. 29. He remains in custody.
A jury delivered the verdict late Saturday afternoon.
The five men and seven women jurors began deliberations on Friday afternoon, after Supreme Court Chief Justice Joseph Kennedy outlined their duties.
Kennedy said there were three possible verdicts: guilty of second-degree murder, guilty of manslaughter or not guilty.
Jurors were back in court Saturday morning to seek clarification on a number of issues, including the definition of second-degree murder.
Kennedy said there was "no question there were unlawful acts" committed, but the question is whether those acts caused Boudreau's death and what the intent of the acts was, the CBC's Wendy Martin reported.
'Let the crabs eat him'
Landry, a crew member on the lobster boat Twin Maggies, had pleaded not guilty in a case the Crown has called a "murder for lobster."
Prosecutor Shane Russell said Landry told police he had been pushed to the limit, and wanted to “cripple” and “destroy” Boudreau, who he suspected was cutting his traps, and if he got the chance he'd “let the crabs eat him.”
In a recorded interview with police, Landry said he fired four shots at Boudreau's boat and then told the captain of the Twin Maggies to ram the vessel.
Landry's lawyer, Luke Craggs, told jurors Thursday that all four shots hit the boat and Landry simply wanted to scare Boudreau, who court heard was cutting lobster traps.
Boudreau's body has not been found.
Dwayne Matthew Samson, the captain of the Twin Maggies, is also charged with second-degree murder.
Samson's wife Carla, owner of the lobster boat and Landry's daughter, faces a charge of accessory after the fact.
Craig Landry, a third cousin of Joseph James Landry, is charged with accessory after the fact.