The UNSC Clearidas was a UNSC destroyer during the Human-Covenant war. During the Battle of Hat Yai the Clearidas ducked and weaved around Covenant forces in low orbit, bouncing off the atmosphere as it dropped its cargo of 100 ODST-filled SOEIV's. After the battle it retrieved the surviving marines and retreated to slipspace.

Sometime after 2535 and the establishment of the Cole Protocol, the Clearidas was ambushed by a Covenant cruiser. Someone high up on the chain of command gave the command to flash unfreeze the ship's ODSTs in case the ship got boarded. However flash unfreezing was incredibly risky, and a third of the ODSTs died. Their lives were wasted, as the Clearidas managed to escape.