Anti-ship missile decoys must bloom faster than a drone can deploy them

Could a UAV or USV deploy a visual and infrared smoke curtain away from a ship?

In principle, but probably too slowly for missile defence; ship-launched rocket decoys can create the required effect much faster and at useful distance.

A UAV or USV could carry obscurants away from a ship. The difficulty is moving into position and blooming the screen within the very short response time of an inbound missile. Warships can carry substantial rocket-launched decoy payloads without the same weight constraints faced by land vehicles. Deployment timing also matters when electronic countermeasures attempt to confuse a seeker. A brief disruption may produce a miss, depending on the missile and its inbound trajectory.