Unless your MOS is 11B, 11C, or 11Z, you are not Infantry in any way, shape, or form. Look on the right shoulder of your dress uniform. If you see something blue wrapped around it, then you are.
88L is Watercraft Operator. Believe it or not, there is water in Iraq and Afghanistan. If the Army didn't intend to use you in/around it, they wouldn't have paid several grand to teach you.
Many MOSs do end up with base security details and things of that nature, as needed. Infantry do as well, but when hadji starts shooting, they not only return fire like the non-Infantry personnel, they also maneuver toward the enemy and kill him.
By the way, Infantry is capitalized. Thank you for your service.