Prowler

The UNSC Prowler was a starship classification within the United Nations Space Command. They were used exclusively by the Office of Naval Intelligence, and were often crewed by select ONI crews.

This is most probably the UNSC equivalent of the Covenant Stealth Corvette.

Role
As per its namesake, it is used to gather electronic intelligence, and its primary role is to stay hidden while safely gathering such ELINT, not to charge into battle, as that would invariably be an irreversibly fatal tactic. Its only combat role, beside active combat monitoring and recording, is discreetly laying minefields of stealthed plutonium HORNET mines. When enemy warships enter these deadly minefields, they will most often be destroyed. This strategem allowed Battle Group Stalingrad to survive longer at the Battle of Onyx.

However, in dire combat situations, the Prowler was armed with "minimal weapons systems". Six of such stealth starships could destroy a single Covenant Heavy Destroyer.

Stealth Systems

 * Ablative baffles
 * Counterelectronic systems
 * Jet-black stealth coating
 * Texture bufferers