Primarily a large surveillance drone, the Sentinel class observation and data collection drone is used by the Black Ops to recon an area and route out possible targets of opportunity without jeopardizing Operatives. Although somewhat frail, the Sentinel is protected by a very powerful shield generator. Capable of shrugging off most if not all small-arms fire. If the drone survives long enough, it will self-destruct upon Charlie Company's arrival, to protect its valuable records and data on its owners.
This enemy does not appear in Recruit Mode.
The Sentinel uses repulsion lifts to keep it hovering off the surface. The high resonance frequencies emitted by Sonic Traps severely disrupts these delicate machines, causes an emergency evacuation protocol to engage. Once a safe distance, normal functions return and the Sentinel will once again seek out targets. This can be used as a delaying tactic by players.
The extremely high damage skills of classes like the Marksman, Demolition, Commando, and Assault are among the most sure-fire way to deal with the Sentinel. Combined firepower from powerful skills and focused weapons fire should deplete the shielding on the drone quicker than it can recharge. Likewise, some skills are powerful enough to kill the Sentinel outright, bypassing its high regeneration rate altogether.
The Black Ops Sentinel utilises Thermal Sighting technology, allowing it to detect Cloaked units up to 11 range, which in turn grants the Black Ops sight of the cloaked marine/s and allowing them to open fire upon him.
The Sentinel is equipped with a cloaking device which allows everyone to see it but they cannot fire at it without detection.
The Sentinel travels by flying. Therefore they are unaffected by terrain and cliffs like ground enemies are.