Navy Commander Philip Wiig has been dismissed from service after a court martial found him guilty of indecent assault.
Wiig was found guilty of indecently assaulting a female colleague four times at a social event at a navy bar in Devonport in 2012.
Today a number of character submissions were made on behalf of Wigg.
However in sentencing Judge Duncan Harvey said "you decided to target this young woman".
"You preyed on her, you humiliated her and you made her feel like an outsider", he said.
Judge Harvey recognised Wiig's 31 years of service, but decided the court must send a very clear message.
Wiig has the right to appeal the sentence before the dismissal takes effect.
The victim, whose details remain suppressed, says she told the commander to "f*** off" after the fourth grope of her bottom and was questioned about it by defence counsel Major Peter Brock.
She told him "if someone grabbed your balls over and over repeatedly, I think you'd be pretty angry as well".