Featured image: “The Spooks” of the USS Fox (DLG–33/CG-33) – Positive Identification Radar Advisory Zone, PIRAZ, Gulf of Tonkin, 1971.  Special thanks to Bill Scholz for allowing his picture to be used on this post.

During the Vietnam War and other major conflicts, the U.S. Navy operated a select group of ships known as PIRAZ stations, short for Positive Identification Radar Advisory Zone. These vessels, often referred to by their radio callsign “Red Crown,” formed the backbone of radar coverage and command coordination for friendly aircraft in designated combat zones.

Positioned strategically offshore, PIRAZ ships were equipped with some of the Navy’s most advanced radar and communication systems of the era. Their mission was clear but demanding — to identify, track, and control all air activity within their zone of responsibility. By doing so, they ensured the safety of friendly forces and provided early warning against enemy aircraft or missile threats.

Key Functions of a PIRAZ Station

Air Traffic Control:
In many ways, PIRAZ ships acted as military air traffic control centers afloat. They guided aircraft through congested or hostile skies, providing pilots with vital information about navigation, refueling, and enemy movement.

Positive Identification:
Using sophisticated radar systems, PIRAZ crews could distinguish between friendly and enemy aircraft — a crucial task in fast-paced, high-stakes aerial engagements. Their accurate identification reduced the risk of friendly fire and improved mission coordination.

Mission Support and Threat Warnings:
PIRAZ ships constantly monitored for threats such as enemy MiGs or surface-to-air missiles (SAMs). They relayed real-time warnings to pilots and coordinated search and rescue (SAR) efforts when aircraft were downed.

Radar and Communications Hub:
Equipped with the Naval Tactical Data System (NTDS), PIRAZ vessels processed and shared radar track data with other ships and command centers. This created an integrated picture of the battlespace, enhancing the Navy’s overall situational awareness.

Helicopter Operations:
Many PIRAZ stations also served as forward bases for helicopters, supporting maintenance, refueling, and rescue operations. This capability expanded their versatility, allowing them to respond quickly to emergencies at sea.

A Legacy of Vigilance

Though technology has evolved and modern command centers now rely on satellite-based systems, the legacy of the PIRAZ ships remains. These vessels — the Navy’s “eyes in the sky” — embodied precision, coordination, and courage, ensuring that countless aviators returned safely from their missions. Their story stands as a testament to the ingenuity and dedication of those who served aboard them, watching the skies so others could fly with confidence.