In early January, the Coast Guard and Department of Homeland Security announced that after February 8, Loran-C would be turned off and unavailable for navigation. The next day, Canada announced that its Loran-C system would be shut down by October 1.

What have we lost? Not much on the local scale, but possibly a lot on the large scale.

Prudent navigators and thoughtful planners understand the value of complementary backups for critical systems. Do we need a back up to the Global Positioning System? Although it may be possible to revert to traditional methods of navigation and piloting such as visual bearings, combined with radar ranges plotted on a paper chart, is it practical? For small vessels, operating at low speeds, it might be feasible. For large vessels and vessels operating in restricted waters at high speeds, it may be not only impractical, but also dangerous.

New England has plenty of fog and restricted waters. Today’s Global Positioning System (GPS) units linked to chart plotters seem amazing to those who years ago were navigating from buoy to buoy, running compass courses and using their watch to time legs. For many, Loran was the first big step forward from this age old practice-we fiddled with a little box and came up with a couple of numbers that gave us a position when we transferred them to the chart. You could record the Loran readings, technically Time Differences (TDs), of a point and steam right back to it whenever you needed to night or day, clear or fog.

Now GPS and the plotter does it all for us with a pretty moving picture of the chart showing any point we want to go back to and the boat moving across the chart. Computer software even allows us to use and display the familiar TDs on the GPS and Loran lines on the plotter.

The next big improvement in navigation systems may be e-Navigation, defined by the International Association of Lighthouse Authorities as, “…the harmonised collection, integration, exchange, presentation and analysis of maritime information onboard and ashore by electronic means to enhance berth to berth navigation and related services, for safety and security at sea and protection of the marine environment.”

Improved safety for large vessels such as tankers and fast vessels such as ferries translates into less risk of expensive and environmentally hazardous collisions and strandings. E-Navigation will also enhance maritime awareness and security.

Very reliable positioning systems are essential to e-Navigation. In the past few years, the Coast Guard has invested $160 million to upgrade the Loran-C system to Enhanced Loran (eLoran) standards. Today 70 percent of the Loran C infrastructure has been upgraded. Enhanced Loran provides accuracy of about 40 feet, comparable to GPS. Enhanced Loran uses an “all in view” mode by which up to 40 signals can be received and compared and also transmits corrections as part of its signal. Modernized equipment makes it less expensive to operate than Loran-C.


Some have embraced eLoran as a back up for GPS, including the Navigation Authorities of the British Isles. The U.S. Department of Transportation asked the Institute for Defense Analysis of Alexandria, Va. to create an Independent Assessment Team to study the issue. This team unanimously recommended that the federal government “retain eLoran as primary backup for critical GPS Applications”

However, the federal government is still studying the issue. LARRY ORLUSKIE 

Larry Orluskie, a Department of Homeland Security spokesperson stated that the department, through its Office of Critical Infrastructure, is once again assessing the need for GPS back up systems and formulating recommendations for candidate back-up systems. There is no deadline or specific timeline for this effort.

Orluskie did confirm that, although the system will be turned off, the Loran-C infrastructure will not be dismantled pending resolution of the GPS back up question, leaving open the possibility of eLoran economically filling that role.

Apart from marine navigation, GPS provides timing information that is used to manage the AIS (Automated Information System) now required on most commercial vessels to broadcast identity, position and movement information as well as in other applications such as ­cell phone networks, pager systems and “smart grid” electric power transmission.

Practical and robust back up for these applications insure that the amenities most Americans expect not be vulnerable to disruption if GPS were unavailable.

The worst-case scenario is that the U.S. will determine that a single GPS back up system is not needed, leaving the country vulnerable to disruption if GPS is interrupted and will not adopt eLoran, going its own way while other major maritime nations go forward with eLoran and e-Navigation. The best scenario is that eLoran is embraced and we move forward with a more robust and reliable navigation infrastructure.

Erno Bonebakker started turning cranks and matching Loran-A waves in the late 1960s, He now revels in the benefits of GPS while working on his seaman’s eye.