Navy Service Stripes

My Grandfather (my mother's father) was a Navy reservist from 43-46. He served aboard the destroyer escort USS Bowers and the destroyer USS Bristol in the pacific. I am currently putting together an Army uniform to honor my paternal grandfather's army service and would like to put together a Navy uniform to honor my maternal grandfather's Navy service. My question is this, would he have earned a service stripe for his three years of service? As always any help is appreciated.

 

That's what I thought however it raises another question. Why would his enlistment last three years rather than four? Did the Navy offer three year enlistments during the war?