Tracking Boat: Find a Boat on a Live Map | MarineRadar
In this article 7 sections
Tracking a boat comes down to one signal and one map. Here is how to find a boat, read what its position is telling you and make sense of the times it doesn’t show up at all.
How a boat’s position reaches your screen
The system behind this is called AIS, short for Automatic Identification System. A transponder on the boat sends out a small radio message every so often. It holds the boat’s identity, its position, its speed and the way it’s heading. Shore-based receivers pick up those messages near the coast, and satellites catch them further out. A tracker collects it all and draws it on a map.
You don’t need the details to use it. What matters is that the position comes from the boat itself, not from a camera or a guess. That’s why it’s usually reliable, and why a boat with no transponder simply isn’t on the map. If you’d like the full background, our guides to what AIS is and what an AIS transponder does go deeper.
Tracking boat positions step by step
You can do this on your phone or in a browser, and basic tracking doesn’t need an account.
- Open the live map. Use the MarineRadar app or the live vessel map on the website.
- Search for the boat. Type its name, or better, its MMSI number, which is the nine-digit identifier a boat broadcasts. Names get reused, so the number points to the right boat. If you only have a name and the search comes back empty, read why a ship isn’t found by name. Our MMSI lookup guide covers how to find the number itself.
- Zoom in close to shore. Smaller boats have weaker signals, and the coast is where receivers are densest.
- Tap the boat icon. The detail card opens with the live position, speed, heading and more. Our guide to reading vessel details explains each field.
- Look at the last updated time. This tells you how fresh the position is, and it matters more than people expect.
- Keep the boat handy. Save it to your fleet so you can open it again in one tap. We cover that in how to add and manage ships.
If you don’t know the boat’s name at all, you can still work it out. Stand where you can see it and use Nearby Ships, which lists vessels around your GPS location. Our guide to finding vessels near you explains that too.
What you can see when tracking a boat
Tap a boat and you get more than a dot. Here is what each piece of the card is telling you.
| What’s shown | What it means | Worth knowing |
|---|---|---|
| Position | Where the boat is now, as a moving icon | Compare it with the last updated time |
| Speed | How fast it’s moving | A figure near zero usually means moored or at anchor |
| Heading and course | The direction the boat points, and the direction it’s actually travelling | They can differ when wind or current pushes the boat sideways |
| Name and MMSI | The boat’s identifiers | The MMSI is the one to search with |
| Boat type | Ferry, tug, fishing vessel, yacht and so on | Set by the crew, so it can occasionally be off |
| Destination and ETA | Where the crew says they’re headed | Typed in by hand, so treat it as a hint |
| Route history | The path the boat has really sailed | Handy for checking where it’s been |
| Last updated | How recent the signal is | The first thing to check |
A couple of extras are worth turning on. Vessel labels put each boat’s name, MMSI or speed on the map so you can read it without tapping, and the guide to symbols, icons and colours explains what the different icons mean. Switching between standard, satellite and nautical maps can make a harbour much easier to read.
Which boats show up, and which don’t
Only boats that broadcast AIS appear. That covers more than people assume. Ferries, tugs, cargo ships, tankers and cruise ships all carry a transponder, as do many fishing boats and yachts. There are two kinds of transponder, Class A and Class B, and the difference affects what you’ll see.
Larger commercial vessels use Class A, which sends often and strongly, so those boats glide smoothly across the map. Smaller craft usually use Class B, which is quieter and reports less often. A Class B boat tends to hop from point to point rather than glide, and it may drop out when it’s far from shore. Our guide to Class A vs Class B AIS lays this out in detail.
Then there are the boats that never appear: dinghies, kayaks, jet skis and many small pleasure boats. Many of them aren’t required to carry a transponder, so there’s nothing to track. If you want to follow one of these, the boat itself needs an AIS unit.
Why a boat sometimes doesn’t appear
When a boat is missing, the cause is usually one of a handful of simple things. Work through them in order.
- It has no transponder. This is the most common reason for small boats.
- The transponder is switched off. Some crews turn it off, and fishing crews sometimes have reasons for it. Our piece on why fishing boats turn off AIS explains.
- It’s out of range. Far from shore, a weak Class B signal may not reach a receiver. See how ships are detected in coastal and deep-sea areas and the difference between terrestrial and satellite AIS.
- The name doesn’t match. Try the MMSI, or a shorter piece of the name.
- The signal has a gap. A ship can briefly vanish and come back, which we cover in why a ship disappears from radar.
None of this means the tracker is broken. It usually means the boat isn’t sending, or isn’t being heard right now.
How to read a position without being fooled by it
A position on a map looks exact, so it’s easy to trust it too much. A few habits keep you honest.
Start with the last updated time. A boat showing a position from five minutes ago may have moved a long way since, especially if it’s fast. Small boats with Class B update less often than big ships, so a slightly old position is normal for them. For more on timing, see how often AIS updates positions.
Next, remember the destination and ETA are entered by the crew. They’re useful, but they can be blank or out of date, and our guide to why ETAs change explains why.
Finally, if a position looks odd, don’t panic. Signals can be delayed or noisy, and we’ve written about why a vessel can appear in the wrong place and how accurate ship location data is.
Handy ways to use boat tracking
People track boats for all sorts of reasons, and some of them are very ordinary.
Following a family trip. If a relative is sailing, a quick look tells you whether they’re underway or tied up at the marina. You can even share a vessel’s location with someone else.
Meeting a ferry. Check how close it is before you leave the house. Keep in mind a tracker shows where the ferry is, not its timetable, which our ferry tracker guide explains.
Watching a yacht or a fishing boat. Both are popular, and we cover the specifics in tracking private yachts and tracking fishing vessels.
Keeping an eye on a group. Sailing events and group trips are easier to follow on one map, and flotilla tracking shows how.
Getting a heads-up. Set a vessel alert around a harbour and you’ll be told when a boat arrives or leaves. You can also replay where a boat has been with route playback.
Tips for better results
- Search by MMSI when you can. It’s the most reliable way to land on the right boat.
- Zoom in near the coast. You’ll get a clearer picture of small boats.
- Check the timestamp before you decide anything. A stale position can mislead.
- Be patient with small boats. Class B boats update less often, so give them a minute.
- On a weak connection, the guide to using MarineRadar on slow internet has some useful tricks.
- Browse the neighbours. The sea traffic live map guide shows how to read the whole area around your boat, and the Ports Directory is handy if your boat is heading into harbour.
CONCLUSION
Tracking a boat is simpler than it sounds. A boat with a transponder sends its position, a live map draws it and you search by name or MMSI. Once you’ve found it, the detail card tells you where it is, how fast it’s moving and when the signal last updated. The one habit worth keeping is checking that last updated time before you trust a position.
When a boat doesn’t show up, there’s almost always a plain reason: no transponder, switched off, out of range or a name that doesn’t match. Work through those and you’ll usually find your answer.
Ready to try it? Open the live vessel map in your browser, or download MarineRadar from the App Store or Google Play and follow your first boat today. You’ll find more walkthroughs in the MarineRadar Resource Hub, and everything starts from the MarineRadar home page.
FAQs
How do I track a boat live?
Open MarineRadar, search for the boat by name or MMSI and tap its icon. If it carries an AIS transponder, you’ll see its live position, speed and heading.
Can I track any boat?
No. Only boats that broadcast AIS appear. Commercial vessels and many fishing boats and yachts do, but dinghies, kayaks and most small pleasure boats usually don’t.
Why can’t I find my boat?
It may have no AIS, the transponder may be off, it may be out of range or the name may not match. Try its MMSI and check the points above.
Is this the same as a boat tracker?
The idea is the same, and both rely on AIS. Our boat tracker guide is a good companion if you want a different angle on the same topic.
Is boat tracking free?
MarineRadar is free to download on iOS and Android, and basic tracking works without an account. The free version shows ads, and optional paid plans add extras. See MarineRadar Free vs. Paid.
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