Which sonobuoys are classified as active buoys?

Active sonobuoys are designed to transmit acoustic signals and then listen for resulting echoes, allowing them to detect and localize submarines or underwater objects. In this context, DICASS (Directional Command Active Sonobuoy System) is the primary example of an active buoy, as it emits sound pings and uses received echoes to determine the position of targets.

The other active buoy types listed in the correct answer include RO (Receiver Only), which does not actively transmit signals, and CASS (Command Active Sonobuoy System), also focused on active sound emitting capabilities.

Understanding the function of different sonobuoys is crucial in anti-submarine warfare, as they each have distinct roles based on whether they are passive (listening only) or active (transmitting and listening). Thus, the correct selection highlights the characteristics and operational uses of DICASS and others for effective naval operations.