A military judge also fined Lt Derek de Jong $5,000 on Tuesday, after the defence and prosecution completed closing arguments.
On Monday, de Jong testified he left his post aboard HMCS Preserver in September 2012. The ship was docked in the Florida Keys.
He said he left his post after he was subjected to deplorable behaviour that included a colleague urinating on his cabin floor.
At the hearing Tuesday, Lt.-Cmdr. Darin Reeves, the military prosecutor, urged demotion for de Jong,but the sailor's defence lawyer suggested that a fine be imposed.
Mitigating factors the defence had wanted the judge to consider were the fact deJong was only AWOL for 30 hours, that his chain of command was informed throughout that time and there were no adverse effects on operations as a result of his desertion.
After going AWOL from HMCS Preserver, de Jong returned to Halifax and has been working at CFB Halifax.