Can GPS be relied on, or can it be turned off, scrambled, or interfered with at the discretion of the US military? Is this a real-life scenario or old-timer tin-hat conspiracism? The following anecdote is a true story from spring 2023. It happened to The Resourceful Sailor’s VHF radio and others in the Salish Sea area with the same equipment. The following is neither an endorsement nor a critique of any company or equipment, but I mention both due to their relevance to the story.

The Resourceful Sailor purchased a Standard Horizon GPX2400 VHF radio new in August 2022. It was affordable and received AIS signals, displaying them on an integrated screen, with the subsequent CPA and TCPA alarms. It had good reviews and was a top-rated radio and very popular. The radio was installed and performed as expected … until spring 2023.

After a dormant winter that kept Sampaguita, a 1985 Pacific Seacraft Flicka 20, dockside with refitting projects, I tested the VHF in early April. Or rather, I tried to. The radio would not boot up as expected. It would either continuously cycle on and off or freeze up in a half-booted phase with no buttons functioning, requiring the power to be disconnected to turn off.

I wasted no time in calling Standard Horizon. The radio was still under warranty and I was leaving on a Vancouver Island circumnavigation in June, followed by a voyage down the west coast of North America starting in August. The technician did the “Is it plugged in?” schtick, suspecting user and installation error on my part. After a thorough (and second) inspection of all the connections, we decided I needed to send it to California for servicing. I immediately did this and received confirmation of its receipt and expected return date. This day came and went with no news, so I called Standard Horizon to inquire. The operator said, “Oh, one of those. Please hold while I transfer you to the service manager.”

It turned out that my radio worked fine in California. However, they had received several similar complaints about this radio model (and only this model) from customers in the Salish Sea area. Enough that the service manager made a map of each location. The center was around the Naval Air Base Whidbey Island and within a 30-ish-mile radius. I was in this radius, and another boater I knew in Port Townsend, WA, with the same radio, was having the same problem. According to the service manager, one customer had trouble on Sucia Island in the San Juan Island group. It worked when returning to Blaine, WA, outside the radius.

Standard Horizon had no solution for the problem. I called the USCG to mention that there were local boaters whose radios may be receiving interference and not operating. Maybe they knew something about it? They were unaware of any issue, nor did they seem to care. I called Seattle VTS (because they have lanes going through this radius) and they were at least cordial and noted it in their log. I did not try to call Naval Air Base Whidbey Island. They are in the business of national security, and it’s generally locally recognized that electrical scrambling warfare exercises occur from this base and the F-18 Growlers that fly out of it.

The service manager theorized that this particular model radio may have been affected due to the nature of its build because of where the GPS signal was processed. However, this was just a theory. I had heard through the grapevine that some equipment from other manufacturers was also malfunctioning, but that was hearsay.

Standard Horizon asked to keep my radio for a while to attempt to find a fix, and I agreed. Near the end of May, the service manager started getting reports that radios in the area had begun functioning correctly again. They returned my radio, and sure enough, it worked. Standard Horizon made no adjustments, so wherever the interference came from, it had stopped. It is unproven that it emanated from Naval Air Base Whidbey Island, but the data and radius lend themselves to the belief that it may have. We will likely never know.

The importance of the story is that radios and GPS signals can and will be interfered with, whether on purpose or inadvertently. Spoofing and jamming reports coming from areas involved in conflicts are becoming common. This story proves it can happen anywhere. The manual states the FCC [Federal Communications Commission] requires that these radios receive interference. This anecdote presents a reminder that dependence on an electrical signal is not self-reliance and comes with its associated risks. For The Resourceful Sailor, interference with the GPS signal is no longer tin-hat conspiracism or a “they will never do that.” Whether it be the operators or the possibility of “bad actors” with increasingly available spoofing or jamming technology, wariness of your GPS may be more and more prudent.

Do you have any GPS interference stories of your own? If so, spread the word, and thanks for reading.

After having used his GPS on a passage in 2023-2024, The Resourceful Sailor shared this comment:
“Modern tech provides incredible tools. I was amazed that I could use GPS to sail a tiny boat to a tiny island in the middle of a huge ocean. After 32 days, there it was, right in front of me. Admittedly, I never worried about it again. But it also may have given me a false sense of independence and self-sufficiency. You always feel like you know where you are with the greatest of ease. It’s difficult to imagine being out there and losing that resource. The Pacific Ocean is huge! I had a sextant and paper charts. Charts are easy for me, but my celestial navigation skills are unproven as they are for many cruisers.“