What you have is a "Hail and Farewell" Bowie Knife.
I don't know if active duty units still have what we used to call the "Cup and Flower Fund" run by the S1. Every officer was docked about $10 - $15 per month in "dues" and the fund bought preapproved gifts under defined situations:
Baby = Silver Plated Cup, engraved with the baby's name.
Death in the immediate family = A wreath of flowers from the Battalion.
Hence the name "Cup and Flower Fund."
PCS = A Bowie knife like the one shown. It comes with a belt sheath that hangs down to about my knees, and a wooden display plaque for hanging in the den. Mine hangs in my office. To be blunt, it's physically unremarkable and you could buy one a a pawn shop for about $25.00.
Looks something like this:
http://www.knivesplus.com/case-knife-plaque-ca-317.html