Writer seeking help... can a ship lose ALL comms?

Hello… I’m a fairly successful writer of crime fiction based in the UK but I’d love to write a story set on a modern ship. I have SO many questions and my ignorance is immense, but I’m hoping for a story in which passengers and crew on board a modern vessel become completely isolated – in other words they lose all communications. There is a baddie involved, so things can be done to existing equipment, but what would have to happen for a vessel to lose any ability to communicate with the outside world?

All help gratefully received.

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Welcome. We could definitely use more sea-based fiction. But it is hard for me to imagine how a ship could lose all comms. Perhaps if an EMP took out all of the communication satellites. That would force the ship to use HF comms on the open sea. But HF is definitely viable.


Fairly easy to lose some comms, more difficult to lose all. Modern satellite communications for email and phone cut out more often than they should. Last year some space debris took out one of the leading provider’s satellites and caused quite the blackout, lasting days for some vessels.

For regular old radio communications, single side band, HF/UHF, etc you would need to lose the primary power supply and the battery back up. Batteries will drain eventually over the course of hours depending on the load after the main power is lost. That leaves you with hand-held satellite phone if you have one.

I think you mean “all” ability.

Sorry you said you’re a writer, so it’s fair under the rules of internet civility, i.e. no civility.

Polar route, 60 degrees latitude plus, north or southern latitude. The best single point failures for all comms are the antennas (absent cell phones, which are unlikely to get signal remotely) grouped so a local damage event can be engineered intentionally or otherwise…

consider also the possibility of forecast (or not) polar cap absorption events which can interfere with Hf and VHF signals.


Weather high wind etc could take out the antennas. As stated already EMP. Losing satellite could happen with loss of all antennas or if the satellite antenna was covered well enough. Ive lost it briefly because of snow or an eagle sitting on it. Sabotage would be the most effective way, but now u still have the issue of personal Garmin Inreaches that dont require an antenna, just line of sight. I could probably overlook that, if it was well written.

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There are also solar events which can cause mass disruption of radio communications.

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Lightning strike.


Even with a lightning strike, I think personal devices would still be a means of commo.

Personal devices like that are still fairly uncommon so it would be believable to not have any onboard.

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I guess I thought they were a little more commonplace. Of the 6 people currently on my vessel, 3 of us have these. We are out of cell service for extended periods of time, especially in the winter.

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You have your work cut out for you. The communication systems on a ship are designed precisely so this sort of thing doesn’t happen.

Long story short, the only way this would happen in the real world is fire or wave damage to the bridge of a relatively small vessel (<300’ LOA/5,000 tons). Incidents like these have happened, but you would need to craft your story to these unusual events. A fire taking out the bridge would mean the ship would be virtually disabled. Ditto bridge windows being smashed by a large wave, wrecking the electronics. Not plausible, but theoretically possible. However, that vessel would need to be more than 10 miles from land or so, or the passengers/crew will use their cells, and the officers will use handheld VHF radios to reach out 20 miles for help.

A longer explanation:
Once you mention ‘passengers’ you made your job more difficult. Personal electronics run the gamut from cell phones to satellite phones. There is no plausible way to disable them all without modern voodoo (EMPs).

Vessels carrying a small number of passengers are found close to land and cell towers. Whatever you do to the ship’s electronics, the passengers can still phone home. Get away from cell towers, head out to the deep ocean, and you avoid the cell problem, But the passenger vessels you are likely to encounter far to sea (cruise ships) carry a greater number of passengers, many with personal satellite comms. Can’t plausibly take them all out at once.

Also, cruise ships will have satellite comm equipment in places other than just the bridge, making it difficult to take these all out at once.

Something often ignored by fiction writers are the ship’s EPIRB(s). If the $hit hits the fan the captain always has the option of activating an EPIRB, knowing the world will come running to his rescue.

The simplest cause to explain your premise is simple sabotage. A confederate of your baddie, a ship’s officer or technician, could in a short period of time surreptitiously disable the GMDSS console, handheld VHFs, and back-up handheld sat comm devices that most vessels carry nowadays. But this would only work if the ship was far away from cell towers. And the saboteur would still need to disable the EPIRB (the author taking care to mention the EPIRBs in the survival crafts).


I wonder what a couple hundred watts of broadband noise on board would do. Possibly with some of it crafted intentionally to make things difficult for satcom protocols…


I came here to mention EPIRBs but freighterman summed it all up nicely. Any ship large enough to be out of sight of land would have a large variety of comms available, and even if the baddie somehow disabled the regular voice communication equipment, the EPIRB is always an option to summon help.


The more I think about how one would make this situation realistic, the more I think the writer needs to befriend a mariner, or continue asking questions here as long as he can get answers. Otherwise the story might end up like the movie Contraband with a captain roaming the decks in dress blues demoting people to cabin boy. Or a worse Wahlberg yet, an electronics technician concerned with cement bond logs.

On the other hand, you obviously need not consider all possibilities just to appease the average reader. Most won’t know the intricacies of modern marine communications.


A well engineered jamming signal transmitted onboard would effectively prohibit reception on all bands and transmission on any device requiring a handshake, which includes cell phones and satcom. It could also be designed to blank out radar reception and positioning. You could still transmit on HF / MF, but not all ship carries such equipment. Cue young officer with an SDR dongle in his laptop and enough insight to diagnose the problem, lamenting the passing of olden days? Never mind, that’s my book idea :stuck_out_tongue:


Yep. Onboard.

A huge thanks all for your help. My ignorance is immense. I’m learning that this may not be possible exactly the way that I want it to happen! But getting my ideas bent out of shape is not necessarily a terrible thing.

@portofdc and others Thanks. A weather or solar event won’t do it because it has to be a planned communication outage. Something Very Bad has to happen in the hours in which they are out of communication.

@shipengr Ah. OK. How easy would it be to sabotage battery back up?

I’m wondering, how software-based are satellite comms? Could the system be brought down in the same way as any computer system can be hacked?

I’m very keen on this, @Klaveness. This sounds very thriller-ish.

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You’re 100% right. As you say, most of us wouldn’t necessarily spot the difference between pure fantasy and the kind of thing that would make an experienced mariner slap his forehead in despair, but I kind of believe if you get the details right the story becomes way more interesting.