Coast Guard Decommissions Loran-C at Jupiter Inlet: Why Losing a Terrestrial Backup Matters
On January 7 the U.S. Coast Guard announced it will decommission the Loran-C navigation program and terminate the Loran-C signal broadcast from Jupiter Inlet, Florida, effective February 8. Federal leaders cite technological progress—most notably the widespread use of the Global Positioning System (GPS)—as the reason for ending a 67-year-old terrestrial position, navigation and timing (PNT) service. Chuck Husick, an electronics engineer and consultant in marine and aviation systems, explains how the decision was made and argues that retiring Loran-C is a mistake.
The Commandant of the Coast Guard has accepted direction from the Department of Homeland Security that Loran-C is no longer a Coast Guard requirement. That step finalizes the plan to remove a proven, resilient PNT system that has reliably supported many maritime and timing-dependent users for decades.
Although Husick strongly disagrees with the Commandant’s conclusion that Loran is no longer required, he recognizes the military chain-of-command context: senior civilian leadership and budget authorities instructed the Coast Guard to end the program, and the service complied with a lawful order.
Accepting the order does not negate the risks posed by eliminating Loran-C, he warns. Many engineers and PNT experts believe losing this terrestrial, high-power, long-range signal will leave the maritime community and other critical infrastructure more vulnerable—especially because GPS, while essential and broadly used, is not infallible.
GPS Vulnerabilities and the Case for eLoran
Husick and other advocates have long argued for maintaining Loran-C and transitioning to eLoran, a modernized, automated, and more robust ground-based system. Official Coast Guard Notices to Mariners have periodically reported significant GPS position errors or interference—sometimes caused by low-level radio-frequency emissions from poorly functioning amplified TV antennas—that affected navigation accuracy.
Accidental interference has also been documented in other settings. In San Diego, for example, a government transmitter once emitted a strong signal that temporarily blocked GPS reception over a substantial area, disrupting cell-phone timing and other services that depend on accurate PNT information.
Beyond accidental interference, intentional disruption—spoofing and jamming—poses a real threat. Tests in the United Kingdom showed that relatively low-power transmitters can feed false GPS positions to nearby vessels, leading them to display wholly incorrect locations rather than simply losing signal. That kind of deception could be particularly hazardous near busy harbors or in-shore traffic lanes, where position information feeds systems such as AIS and bridge control centers.
Natural phenomena are another source of risk. Solar storms and intense solar flares have a record of disrupting long-range communications and power distribution; historical and modern events have shown that space weather can impair radio and navigation systems. Because we cannot predict when accidental, malicious, or natural events will degrade GPS coverage, Husick argues it is prudent to retain a complementary terrestrial PNT system rather than rely on a single source.
Why Loran Lost Its Champion
Husick stresses that the Coast Guard is not solely to blame for Loran’s termination. The program lost political and budgetary champions over time. In government acquisition and budgeting, large programs typically survive when they have influential advocates inside the agencies and on Capitol Hill. Loran-C, despite decades of service, became an orphaned program without the internal support and line-item budget structure needed to survive competing priorities.
From the Coast Guard’s perspective, mission priorities center on platforms and capabilities that are immediately necessary for operations—aircraft, cutters, and the support that keeps them ready. So long as GPS appears to meet operational needs, there is little institutional incentive to keep funding a separate PNT system. At the Department of Homeland Security and in the Office of Management and Budget, budget decisions and a drive to cut costs made Loran an easy target. Officials looking to reduce federal expenditures calculated that terminating Loran could yield future savings, and without strong advocacy the program was cut.
The Illusion of Complete Security
Husick cautions that budget-driven decisions can create a false sense of security. DHS will invest heavily in programs and devices intended to deter threats, but if those investments fail to acknowledge core vulnerabilities—like single-point dependence on GPS—then any security gain may be illusory. Maintaining a terrestrial backup such as eLoran would provide redundancy against jamming, spoofing, equipment failure and certain solar effects, strengthening resilience across maritime navigation, communications networks and critical infrastructure.
While the Coast Guard has complied with policy direction, many users and technical experts will now need to focus on the consequences of losing Loran and consider ways to mitigate the increased risk that one-source PNT dependence creates.
Stories in this issue:
- The death of Loran
- Youngest, smallest, longest
- Face-to-face with a great white
- How young is too young?
- Soundings revamps online boat search tool