USS SIERRA AD-18 HAT - NAVY BLUE - Veteran Owned Business. Navy Blue Cap High Detail and Impact - USS SIERRA AD-18 HAT. 8 Rows Stitching on Visor and Pro Stitch on Crown 5 panel hat. USS SIERRA AD-18 HAT - Adjustable Size, Navy Blue Golf Style. HatnPatch Is THE Veteran Owned and Operated Family Business - 2 Generations of Retired Marines - We Ship Your Order Within 24 Hours And Usually The SAME DAY!