How much depth excess is required for usable CZ?

The required depth excess for usable Controlled Zones (CZ) is established to ensure that the acoustic environment is appropriate for operations while minimizing interference and maintaining safety. In this context, the significance of 200 fathoms indicates that this is the minimum depth that provides a sufficient buffer zone beneath the surface to account for various factors impacting acoustic propagation, including bottom effects and surface conditions.

The addition of 200 fathoms ensures that the underwater environment is adequately isolated to allow for effective acoustic measurements or operations. This depth not only accommodates variations in seabed topography but also helps to mitigate the impact of surface noise and other disturbances that could adversely affect the quality of the acoustic data being collected.

Choosing 200 fathoms as the standard reflects a balance between operational effectiveness and safety considerations, making it a well-informed guideline for maritime practices.