Navigation in times of war
The publication of the article on GPS problems in Windassist led to much discussion. The news about the closure of the Strait of Hormuz brought questions like “GPS no longer works there, how will those ships navigate to the high seas soon?” The editors went in search of answers.
Remarkably, not everyone wants to give information by name, with both the Navy and the shipowners keeping a low profile, for understandable reasons. First the follow-up to the previous article. Besides the areas with GPS interference in the western Mediterranean and the Persian Gulf, the most important area for our readers is the Baltic Sea.
The Baltic Sea under attack
Russia has been showing its power in the Baltic Sea for several years. Many NATO countries are feeling the effects of Russia’s hybrid war, and the threats it poses to everything, from internet stability and energy to transport infrastructure. In November, the Norwegian foreign ministry explicitly warned that Russia was interfering with GPS systems. “In our border area, there is almost continuous GPS jamming or spoofing, which makes it difficult for civilian traffic” explained Eivind Vad Petersson, state secretary at the foreign ministry.
And alternative from the old box
Alternative systems are also being reintroduced, notably Loran. Dating back to the early 1940s, the system used low-frequency land-based radio transmitters to provide position information based on time differences between stations. GPS ended Loran, and it was discontinued in the US and UK more than a decade ago, but resistance to interference has led to a new generation of a highly accurate enhanced system, or eLoran.
It is considered so vital that the UK government announced in November 2025 that it would allocate £71 million of £155 million of funding to develop a national eLoran programme. eLoran is already in use in South Korea and China, and some other countries have had it as an alternative for some time.
A submarine alongside the boat
Anke Schekahn, together with her husband, was on watch as they sailed their ship from Władysławowo in northern Poland to Klaipėda in Lithuania in the early summer of 2025, en route to Estonia. In the distance was the coast of Kaliningrad, the Russian exclave sandwiched between Poland and Lithuania on the Baltic Sea. The German couple were sailing through Russia’s exclusive economic zone, but outside its 12-mile territorial limit, when they spotted a strange-looking silhouette on the horizon. Neither of them could imagine anything about the low, dark object until it came closer. As it approached, they realised it was a partially surfaced submarine. The plotter gave no position and there was no AIS signal.
Navigation in the Gulf
The Iran-USA-Israel war has been prominent in the news and has confused shipping. How do you navigate a supertanker when the blockade has been lifted but navigation is still disrupted? We got in touch with a Dutch ship now waiting in the Persian Gulf. The ship has two -completely separate- ECDIS systems, which, according to the helmsman, are proving unreliable.
“We luckily got recent paper charts on board in Rotterdam and it also turned out we have a sextant somewhere. We just started practising; the sextant is mainly used to make horizontal bearings on objects ashore and put them into the paper chart. From astronavigation it hasn’t come yet, it’s been ages since I was in a classroom.”
When asked, Jan Maat of Harri Trading explains how the many ships where ‘flat navigation’ has fallen rather into disuse are still being helped. “The international network of chart agents that works with the UKHO (the UK sea chart maker) delivers paper charts and navigation instruments ‘as we speak’. Delivery is made with specialised carriers through the Gulf States. We work with our colleagues in Japan, South Korea and Indonesia. For ships to the Baltic Sea, we see a multiplication of the number of paper charts we supply.”
Knowledge of navigation
The question remains whether contemporary digitally organised mariners still master that flat navigation and astronavigation. From the US Navy, we know that -above a certain rank- astronavigation is again a mandatory component. We did not get confirmation from the Dutch Navy whether this is also the case in the Netherlands. What is certain is that ‘celestial’ has been removed from the curriculum at nautical colleges in the Netherlands. Fortunately, there is an exception: the Enkhuizen Nautical College.
Sources: Yachting World, Harri Trading, Rotterdam
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