The Supply Caches are a feature in Halo 3: ODST. They are secured rooms in the city of New Mombasa, filled with supplies such as weapons, ammunition and in some cases, Mongooses. They are unlocked by finding Audio Logs. There are 7 available supply caches. The supply caches are marked on the map with the Superintendent icon. The interior, and sometimes the immediate proximity, of a Supply Cache is marked with symbols used by the Huragok, the center one of which usually depicts the Superintendent's avatar. To open the door, the Rookie must stand in front of the door's camera. The Superintendent will then open the door for the Rookie if he has unlocked this cache by finding that Cache' needed Audio Log.
The Supply Caches contain enough weapons to supply up to 4 players from empty. All six Supply Caches contain several identical items:
While two of each cache will contain one of the following:
- M274 Ultra-Light All-Terrain Vehicle x2
- Sniper Rifle System 99D-Series 2 Anti-Matériel x2
- M41 SSR MAV/AW x2
It should be noted that, unless taken (exchanged for another weapon), the M6C/SOCOM and M7S Caseless Submachine Gun will not disappear, no matter how much ammo is taken.