The Coast Guard is establishing temporary, 500-yard radius, moving security zones within the navigable waters of the Corpus Christi Ship Channel and the La Quinta Channel. The security zone is needed to protect certain vessels carrying cargo which poses risks such that it requires an elevated level of security to protect the cargo itself and the surrounding waterway from terrorist acts, sabotage, or other subversive acts, accidents, or events of a similar nature. Entry of vessels or persons into these zones is prohibited unless specifically authorized by the Captain of the Port, Sector Corpus Christi or a designated representative.
Source: Federal Register USCG
Link: Security Zone; Corpus Christi Ship Channel, Corpus Christi, TX