Eerie encounters on the high seas: when a relaxed sailing trip on the Atlantic turns into an encounter with the Russian shadow fleet. A conversation about sabotaged radio traffic, middle-finger politeness and a 280-metre tanker that comes far too close to a yacht in the middle of the night.
In September 2025, Jens Gerdau and his wife Heidi are travelling from the Algarve to Madeira in their Bavaria C42. After passing through the traffic separation scheme off Cabo de São Vicente, a five-hour encounter begins that will stay with the couple for months to come: Russian folk music on channel 16, a whistled "Internationale" over a pan-pan message, complete blackout of VHF communication - and finally the ominously close passage of the "Swiftsea Rider" in the moonless night. A 280-metre tanker, later identified as part of the Russian shadow fleet, equipped with special radio equipment.
YACHT: Tell me, Mr Gerdau, why are you listening to songs on Channel 16 in the middle of the Atlantic?
Jens Gerdau: That surprised us too! We were travelling at the most south-western tip of Europe, on our way from the Algarve to Madeira. There is a lot of shipping traffic in this sea area - due to the junction at Cabo de São Vicente, you can hear radio traffic all the time. Ships call each other on channel 16 and arrange to meet on working channels, usually to discuss overtaking manoeuvres.
When we had just passed the traffic separation scheme, we suddenly started to hear Russian on the VHF radio - at least what we thought was Russian. At first it wasn't noticeable, even on channel 16 people sometimes communicate for a minute or two. But this time the whole thing mutated into a continuous chatter. After about half an hour, the conversation was replaced by music - folk song-like music. That's when we realised: this is no longer a coincidence, it's intentional.
What exactly did you hear?
It went on for about five hours - palaver with lots of laughter alternated with music, interrupted only by short breaks. We asked ourselves: Why don't they just overlay everything with continuous noise? It was completely anti-subtle - like a calling card. The radio traffic became louder and louder, and meanwhile the "Swiftsea Rider", a 280 metre long tanker bound for Murmansk - the well-known Russian oil loading port in the North Sea - approached us. We suspected that this was the source of the disturbance.
Was there no further radio traffic to be heard on channel 16?
Hardly. But during one of the breaks, an urgent message came through - we heard "Pan Pan" three times. We had almost completely turned off the radio and turned it up again at that moment. But the rest of the message disappeared under a very skilfully whistled version of "Internationale". We looked at each other in bewilderment. To interfere with such a report - we found that unbelievable. We were negatively astonished, to put it mildly.
How did you feel in this situation?
As the tanker approached, it became increasingly uncomfortable. There was no other ship in the vicinity that could have been affected by the interference. We realised that there was a colleague over there who wasn't following the rules. That's very unpleasant. You can always somehow avoid a tanker, but we realised that they had paralysed the entire GMDSS. We couldn't hear any other radio messages. And when an emergency message was then cancelled - we felt helpless. We were angry. And then this ship came towards us. The situation was anything but pleasant.
What were the other conditions like during this time?
We were sailing extremely low before the wind, had a swell of three metres from the north-west and a wind sea of two metres from astern. The boat was really soughing, so you don't want to leave the cockpit.
We had already seen at a relatively high distance that the ship would come very close to us - the CPA - the closest point of approach - was well under a mile. On the Atlantic, we are used to commercial vessels behaving professionally and changing course well in advance. That wasn't the case here. So we slowed down and hoped that he would pass in front of us. We would have liked to radio him to ask if he could even see us on the AIS - but we couldn't because of the constant interference.
In other words, they passed each other without consulting each other on the radio?
Not quite. Three miles away, the music suddenly stopped. Just seconds later, we got the call: "DeePee, DeePee, Swiftsea Rider!" We reported in immediately, switched to channel 10 and then the captain asked in perfect, accent-free English: "Sir, good morning, sir. What is your intention, sir?"
What was going through your head?
What is my intention? We are shown as a sailing boat on his devices, we are not travelling any strange courses. Instead, he almost runs us over, ignoring all the rules of right of way, and calls me "sir" three times in a very friendly manner. If you listen to the radio traffic down there, the English is usually very dominated by the respective accents. In this case, it was like listening to an Oxford English teacher. In terms of style, I would say: a cultivated middle-finger friendliness. I looked at my wife and said: "He's taking the piss!"
What did you answer then?
Well, our boat measures 12 metres, his tanker is 269 metres longer. He shouldn't start turning around now. I told him that we had reduced the sails to reduce the speed and that he should please maintain his course and speed. We would pass behind him. He repeated my request, asked if he had understood correctly and thanked me for my co-operation.
How did the passage go?
It turned out to be closer than expected. From one second to the next, the roar of his engine roared over, and the increasing wind unfortunately pushed us along far too quickly. We tacked and sailed parallel to his course for a few minutes - our last-minute manoeuvre. It was moonless, completely black, no outlines to be seen, just lights. Slowly, the tanker caught up with us. Its engine roared menacingly close. Then it was through. The distance was ultimately less than a mile on the passage. We dropped back down and saw him directly above the reflection of our position lanterns - just a few hundred metres away. I have this wheelhouse in my mind's eye and the words "No Smoking".
Never have we felt so vulnerable at sea, never were we so happy to look a ship on the stern. It remained quiet on the VHF afterwards. I made coffee in the middle of the night - that never happens. We slowly regained our composure, but that night was a frequent topic of conversation in the weeks to come.
How sure are you that the tanker is one of the Russian shadow fleet?
We did some research after the encounter: Lloyd's List lists the "Swiftsea Rider" - as suspected - as part of the Russian shadow fleet. The ship, which is sanctioned by the EU and UK, is used alongside another tanker for espionage activities against NATO naval and air forces and is said to have special radio equipment that makes this possible. The other tanker was the "Eagle S" - known from the Estlink incident in the Gulf of Finland. It has since been scrapped.
According to Lloyd's List, the ship currently registered in Cameroon is sometimes travelling with fake IMO numbers to make tracking more difficult. It is currently travelling as "Nosu", but keeps using different names. After our meeting, it actually sailed to Murmansk, travelled to a Seychelles atoll and spent a long time in Oman. It is currently anchored off Tallinn and Helsinki - in the middle of the Baltic Sea.
Has a queasy feeling remained?
That was an absolutely isolated incident, we assume. We were not aware that something like that could happen in the area where we sail. Shadow tankers, GPS jamming - we had always limited that to somewhere in the Baltic Sea. By the way, we didn't have any GPS jamming, it was really just radio interference. But we wouldn't have expected it down here.
We have spoken to other sailors about this, but we have not heard of any similar incidents. Another sailor we saw on the AIS must have noticed it, but we didn't catch him afterwards.
We haven't changed anything in our direct behaviour. We now take a closer look at the ships that pass us. And we've got ourselves a Starlink. We didn't actually want that, but having another communication channel and being able to call up our local position via satellites that aren't affected by GPS jamming - that's a little bit of security in case we get into a situation like that again.
Ursula Meer
Redakteurin Panorama und Reise
