"I believe the basis for the appeal will be the judge's charge to the jury and the legal instructions she gave to them," lawyer Glen Orris told CBC News.
Karl Lilgert was the officer in charge when the Queen of the North ferry struck Gil Island and sank just off the B.C. coast in March 2006, killing two people. Passengers Gerald Foisy and Shirley Rosette are presumed to have drowned.
The trial began in January and the jury took six days to reach its verdict.
Lilgert's sentencing hearing is scheduled for June 21.