John Alan Jones, 57, a former supply officer on the HMAS Sirius, was demoted from lieutenant commander to lieutenant ahead of his dismissal from the navy and fined $2,000, after being found guilty on seven of the nine counts against him, The Canberra Times reported.
Jones could be a free man after serving a year behind bars if he earns time off for good behavior.
He acknowledged he ordered the young female underling to remove her blouse and expose her bra, and spanked her on four occasions -- three times on her bare buttocks -- while she counted the blows and said she was a naughty girl, but he argued he did it to instill discipline in the headstrong woman, the newspaper said.
Jones' attorney, Lt. Cmdr. Alister Abadee, maintained the spankings weren't sexual.
The victim, whose name wasn't made public, testified she was afraid of Jones, thought no one would believe her story and was so distressed by the spankings she considered suicide.