Fishing Vessel Tracker: How to Follow Fishing Boats Live
In this article 6 sections
A fishing vessel tracker runs on the same system as any other ship tracker, AIS, and that is both its strength and its biggest blind spot. Type a trawler’s name into MarineRadar and, if the boat carries an AIS transponder, you can watch it work a ground in real time: speed dropping to two or three knots, the course doubling back on itself, then a straight run home once the hold is full. The catch is that carrying AIS is optional for most fishing boats in most of the world, so a tracker built on it will always show a slice of the fleet rather than the whole picture. This guide covers which fishing vessels actually show up, how to find and read one on a live map, and why a boat you were watching yesterday can vanish from the screen without anything having gone wrong.
AIS, VMS and a Fish Finder Are Three Different Things
Search “fishing vessel tracker” and three unrelated products answer. A fish finder is sonar bolted to the hull, showing the skipper what is under the boat. It is private equipment with no connection to anything on land, and it has nothing to do with tracking a vessel from shore.
A Vessel Monitoring System, or VMS, is closer, but it is not public. Fisheries authorities require licensed commercial boats to carry a VMS unit that reports position by satellite straight to the regulator, usually every one to two hours, so inspectors can confirm a boat stayed out of a closed area or inside its quota zone. That feed belongs to the regulator. It is not broadcast, and no public map, including MarineRadar, can show it.
AIS is the one a live map actually uses. It is a VHF broadcast, picked up by coastal stations and satellites and republished to anyone with a receiver, which is why MarineRadar can show an AIS-equipped fishing boat the same way it shows any other vessel on the water. The difference is simply who is required to carry the equipment, and for fishing vessels that answer is far narrower than for cargo and passenger traffic.
| System | Who requires it | Who sees the data | Shows on MarineRadar? |
|---|---|---|---|
| Fish finder | Nobody, it’s optional gear | Only the crew on board | No |
| VMS | Fisheries regulators, for licensed vessels | The regulator only | No |
| AIS | Varies by size, flag and region | Anyone with a receiver | Yes, if the boat carries it |
Which Fishing Boats Actually Carry AIS
Global shipping has one simple AIS rule: SOLAS requires it on vessels of 300 gross tons or more on international voyages. Fishing boats are mostly excluded from that rule outright, because they are neither cargo nor passenger vessels and rarely hit that tonnage anyway. What fills the gap is a patchwork of national and regional requirements, and it varies more than most people expect.
The European Union has required AIS on its own fishing vessels of 15 metres or more in length since 2014, which is why European trawlers and seiners are some of the most consistently visible fishing boats on any public map. Several other coastal states apply a similar size threshold to their domestic fleets, usually somewhere between 15 and 24 metres, largely for collision-avoidance in crowded waters rather than to help anyone watch them from a web browser. Below that threshold, carriage is rare. The small, open or wooden-hulled boats that make up most of the world’s artisanal fishing fleet were never built to carry a transponder and never required to, so the overwhelming majority of fishing vessels on the water today are simply not part of the AIS picture at all.
In practice this means a fishing vessel tracker is strongest on industrial-scale fleets: factory trawlers, large seiners and longliners, and the bigger boats flagged to countries with a size mandate. A fishing vessel tracker is close to useless for the small-boat fleets that still land most of the catch in coastal Asia, West Africa and much of Latin America, and no amount of searching will change that, because the boats are not transmitting.
How to Track a Fishing Vessel on MarineRadar, Step by Step
Once a boat does carry AIS, finding and reading it takes a few minutes.
Step 1: Get the boat’s name or MMSI
A name is enough for most searches, but fishing fleets reuse names more than cargo lines do, so an MMSI resolves it precisely if two boats share a name. Many smaller fishing vessels never carry an IMO number at all; IMO is assigned by hull size and vessel type, and a lot of working fishing boats fall below the threshold.
Step 2: Search it on MarineRadar
Open the live map and search the name or MMSI. If the boat is transmitting and within coastal or satellite coverage, its position appears with speed, course and the time of its last report.
Step 3: Check the ship-type tag before trusting the name
MarineRadar reads the vessel type straight from the AIS message and tags it on the map, so a quick glance confirms you have a fishing vessel and not a similarly named workboat or yacht. The full list of what each tag covers is in our guide to AIS ship-type categories.
Step 4: Read the speed and course pattern, not just the dot
A fishing boat’s movement looks nothing like a cargo ship’s. Slow, uneven speed and repeated turns usually mean it is working a ground; a steady course at higher speed means it is steaming out or heading home. The map’s vessel labels show speed and course at a glance, which is the fastest way to tell the two states apart without watching for several minutes.
Step 5: Set a zone alert instead of refreshing the map
If you only care about one stretch of water, a port approach or a specific bank, draw a zone and MarineRadar will notify you when a vessel you are following enters or leaves it, rather than you checking back every hour.
What a Fishing Vessel's AIS Broadcast Actually Contains
Once a boat is transmitting, the message itself is the same format every vessel sends.
- Position, speed over ground, course and heading, refreshed every few seconds to a couple of minutes depending on AIS class.
- Name, MMSI and vessel type, used to confirm you have the right boat.
- Navigational status, more useful here than almost anywhere else: a boat flagged engaged in fishing rather than under way using engine tells you it is working before you have even checked the speed.
- Destination and ETA, usually blank or stale on a fishing boat, since there is no terminal slot to hit and no commercial reason to fill the field in.
- Draught, which matters less here than on a loaded tank vessel, since catch weight changes it only slightly.
The field most worth watching is simply the time of the last report. A report that stops updating for an hour or more, well within coastal range, is a stronger signal that something changed than the position itself.
Reading a Fishing Vessel's Track: Working a Ground or Steaming Home
A cargo vessel’s track is almost boring by comparison, a straight line at a steady speed between two ports. A fishing boat’s track tells a story if you know what to look for. Trawlers towing a net typically run at two to five knots in long, repeated passes or wide loops over the same patch of seabed, and the speed barely varies because towing a net at a steady pace is the whole point. Purse seiners look different again: a tight, fast circle as the net goes round a school, then a dead stop while it is hauled, then a short move to the next mark. Longliners show a slower, more irregular pattern with frequent short stops as gear is set and retrieved along a line that can run for miles.
Steaming looks nothing like any of that. A boat holding eight to twelve knots on a straight course, whether outbound at the start of a trip or inbound at the end, is in transit rather than working. The shift from a fishing pattern to a steady transit course is usually the clearest sign that a boat has finished for the day or the trip and is headed for port, often hours before it actually arrives.
Why a Fishing Boat You Were Watching Disappears
A gap in the track rarely means the boat sank. The ordinary explanations, in order of how often they happen:
- It never had AIS in the first place, and what you were watching briefly was a nearby AIS-equipped boat whose track crossed its path.
- The crew switched the transponder off, which is unfortunately common on fishing grounds. Good fishing spots are a competitive secret, and some skippers turn AIS off rather than broadcast exactly where the catch is running, even where carrying the unit is mandatory.
- The boat moved beyond coastal receiver range, typically 20 to 40 nautical miles offshore, before a satellite pass picked up the next report, leaving a longer gap than you would see near a port.
- It is flagged to a country that mandates AIS but enforces it loosely, so the unit is on board and sometimes on, sometimes not.
None of these looks different from the map’s point of view. A gap is a gap, whether it is caused by missing equipment, a flat battery, deliberate silence or a satellite pass that has not come round yet. Treat the last known position as exactly that, not as evidence of anything beyond it.
Who Actually Uses a Fishing Vessel Tracker
Fisheries researchers and conservation groups are the heaviest users of public AIS for fishing fleets, because it is the only broadcast data available to anyone outside a fisheries ministry. Initiatives such as Global Fishing Watch have spent years turning exactly this patchy AIS picture into estimates of where industrial fishing effort is concentrated worldwide, precisely because VMS data stays locked inside national regulators and AIS is the only public substitute. Seafood buyers and processors use the same public feed more narrowly, timing a purchase or a delivery slot around when a specific boat is actually due back rather than trusting a schedule written days earlier, and families of commercial fishers check a known boat’s position when the forecast turns, less to monitor the catch than to confirm the crew turned for shelter rather than pushed on. None of it needs anything from MarineRadar beyond what any AIS-equipped vessel already broadcasts; the value is in finding it quickly and reading it correctly.
Watching a Small Fleet Together
Operators running more than one boat rarely want to search each name separately. Adding every AIS-equipped boat in a small fleet to a single group lets you see all of them on one screen and get one alert feed instead of several, which is the same approach covered in our guide to flotilla tracking. It works for three trawlers out of the same harbour exactly as it works for a cargo line’s fleet, with the same caveat as everywhere else in this guide: a boat only joins the group’s picture once it is actually transmitting.
Conclusion
A fishing vessel tracker shows you the boats that carry AIS and nothing about the ones that don’t, and for this fleet type that gap is larger than for almost any other vessel class on the water. Once you know a boat is equipped, finding it, reading its speed and course correctly, and setting an alert instead of watching the map takes a few minutes. Knowing which boats are simply never going to appear is what stops you mistaking an equipment gap for a vanished vessel.
MarineRadar is free to start on Android and iPhone. If the boat you want is AIS-equipped, search its name and you will see it move within seconds. For general-purpose tracking across boat types, our boat tracker guide covers the rest of the fleet.
FAQs
Can you track fishing boats?
Yes, but only the ones broadcasting AIS. Large commercial trawlers, seiners and boats flagged to countries with a size-based AIS mandate are usually visible on a public live map. Most small-scale and artisanal fishing boats worldwide never carry a transponder and will not appear no matter how the search is phrased.
How do I track a fishing vessel?
Search its name or MMSI on MarineRadar; if it carries AIS, its position, speed and course appear live.
Is there an app to track fishing boats?
Yes, MarineRadar, free on Android and iPhone.
Why do some fishing boats not show up on a tracker?
Usually because they never carried AIS to begin with. Below roughly 15 to 24 metres, depending on flag and region, carriage is mostly optional, and the small boats that make up most of the world’s fishing fleet fall under that line.
What is the difference between AIS and VMS for fishing vessels?
AIS is broadcast publicly and is what live maps like MarineRadar use. VMS reports only to the fisheries regulator that required it and is never public. A boat can carry both, either, or neither depending on its size and where it is licensed to fish.
Why would a fishing boat turn off its AIS?
Mostly to keep a good fishing ground secret from competitors, since the position becomes visible to anyone else with a receiver the moment it transmits.
Can I track illegal fishing with a vessel tracker?
Only indirectly, and only for the minority of boats that carry AIS at all. A public tracker can show a licensed vessel’s movements, which is exactly how researchers flag suspicious patterns, such as a boat crossing into a closed zone or loitering near a border it has no business near. What it cannot do is see a boat that has switched the transponder off or never carried one in the first place, and that gap, not a visible-but-deceptive track, is how most unreported fishing actually stays hidden from any public map.
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