How can I track a ship live for free?

Open shiptrail.io, type the ship's name, MMSI number, IMO number or call sign into the search box and pick her from the list. It is free, with no account to make. The map shows the ships that radio receivers on land can hear.

How do I find where a ship is right now?

Search for her on the map. Her card shows her last reported position, speed and course, and her page gives the time of her last report. If she is not on the map, she has most likely sailed out of range or switched her transponder off: Shiptrail drops a ship 3 hours after her last report if she was moving, 6 if she was stopped. Her page, if she has one, says when she was last heard.

The Automatic Identification System: a radio transponder that broadcasts a ship's name, position, speed, course and destination so that other ships and stations on shore can see her. What ship tracking is , above, says more.

What is the difference between an MMSI and an IMO number?

An MMSI is a nine-digit radio identity set in a ship's transponder. Its first three digits show the flag, so it changes if she changes flag. An IMO number is seven digits and belongs to the ship's hull: it is never reassigned to another ship and stays the same when she changes flag. A small boat may have an MMSI and no IMO number. Either one finds a ship in the search box.

Can I track a container?

Not here. AIS is for ships, not boxes, and a container carries no transmitter. Your booking or bill of lading usually names the ship carrying it, so search for the ship's name. If you type a container number into the search box, it tells you the same.

Why can't I find my ship?

Most often she is out of range of every receiver, or has not been heard in the last year, so she has no page. If you typed an IMO or MMSI number, the box says when no ship with that number has been heard. Otherwise check the spelling against your booking: the box forgives a small typo, and it tries your words again without a title such as MV or a word such as yacht on the end.

How up to date is a position?

The map hears of a new report within seconds of Shiptrail receiving it, but a ship reports only every few seconds to a few minutes, and less often in weak coverage, so a position can be minutes old. Each page shows the time of the last report, and a mark fades the longer ago a ship was heard.

Why does a ship vanish from the map?

She leaves the map 3 hours after her last report if she was moving and 6 hours if she was stopped. Usually she has sailed out of range or her transponder is off. Her page stays and says when she was last heard.

Does Shiptrail cover the open ocean?

No. It hears ships through receivers on land, which reach about 20 to 40 nautical miles, so a ship in mid-ocean is not seen until she comes near a coast. Services that cover the open ocean buy satellite data, which Shiptrail does not.

Can I use it to navigate?

No. Positions are relayed, can be minutes old and cover only part of the sea. Use official charts and the ship's own equipment.

Can I track a yacht, a fishing boat or a naval ship?

Only if she has an AIS transmitter that is switched on and within range of a receiver. A boat that carries one by choice shows up like any ship, and one that does not cannot be seen, so a boat missing from the map is not necessarily missing from the sea.

There is no app to install. Shiptrail works in the browser, and on a phone you can add it to the Home Screen so that it opens like an app. About has the steps.

How to track a ship live for free: a plain guide

The short answer

To track a ship live and for free, open the Shiptrail map and type her name into the search box at the top. Her MMSI number, her IMO number or her call sign works too, if you have one of those. Pick her from the list and the map moves to her, with a card that says where she is, how fast she is going and where she is headed. There is no account to make and nothing to install.

One thing to know before you start. Shiptrail hears ships through radio receivers on land, so it follows ships near coasts. A ship in the middle of an ocean is out of range until she comes back toward land. The sections below say what that means in practice.

How to track a ship on Shiptrail

Open the live map and searchGo to shiptrail.io and click the search box at the top. Type a ship's name, her MMSI number, her IMO number or her call sign, or a port or a place. You do not need the whole name, and a small typo is forgiven. Many ships share a name, so a number is the surest way to find the one you mean, and an IMO number is the best of them if your booking gives you one. The box reads a number with its label in front, IMO or MMSI, as well as the number alone.
Pick her from the listWith nothing typed yet, the box lists the ships you opened from it before, kept on this device only. Once you type, the ships that are on the map now come first. A ship that is not on the map at this moment, but that Shiptrail has heard in the past year, is listed after them with the day she was last heard, and choosing her opens her page. Choosing a ship that is on the map moves the map to her and opens her card.
Read her cardThe card gives her name and type, a photograph if there is one, where she left from and where she is bound, and her speed and course. Only some ships have a photograph, so do not read anything into a missing one. The button marked Full ship details opens her own page.
Open her pageEach ship Shiptrail has heard in the past year has a page of her own. QUEEN MARY 2 is at shiptrail.io/vessel/310627000-queen-mary-2, for example. It is an ordinary page of text, so it opens quickly and you can send it to someone. It gives her last known position and when it was reported, her voyage, her recent voyages between ports, the weather where she is, the ships near her and her AIS details. A small map draws her last 24 hours as a line.
Watch her on the mapWhile the map is open, new reports reach it within seconds, and her mark and card update on their own. The map does not follow her, though, so zoom out or drag it if she sails off your screen. A mark is at full strength if she was heard in the last five minutes and fades the longer ago she was heard, to about a third at an hour, so a pale mark is an old position. To send someone straight to her, give them an address like shiptrail.io/?ship=310627000, which ends in her MMSI.
Look at a portIf you would rather watch a harbour than one ship, search for a port's name or open Ports. A port's page lists the ships in port now, the ships on their way there, and the ships that left in the last 48 hours. Honolulu is a good one to look at.
Narrow the map with filtersFilter, in the map's top bar, thins out the crowd. Its choices are Highlight, Vessel type, Length, Motion, Canals and Chokepoints. Under Highlight, Fastest 50 shows the 50 quickest ships heard in the last hour, and Famous ships shows a hand-picked few, which the Famous ships page lists.

What ship tracking is

When people talk about tracking ships, they nearly always mean AIS, the Automatic Identification System. A ship with AIS carries a small radio transponder that keeps announcing who she is, where she is and where she is headed, so that other ships and stations on shore can see her. The international safety rules (SOLAS) require one on ships of 300 gross tonnage and over on international voyages, on cargo ships of 500 and over that stay in home waters, and on all passenger ships. Plenty of smaller boats carry one by choice.

Who she isHer name, call sign, MMSI, IMO number, type and size, sent about every six minutes.
Where she isHer position, speed, course and heading. A large ship sends them every 2 to 10 seconds under way and every 3 minutes at anchor. A smaller Class B unit sends about every 30 seconds when moving, so a boat that carries one shows up less often.
Where she is goingHer destination and arrival time, which the crew type in by hand, so they can be out of date.

Anyone with a receiver in range can listen. The radio is VHF, which travels in a straight line, so a receiver on land hears ships within about 20 to 40 nautical miles. Satellites can hear ships far out at sea, but that data is paid for, and Shiptrail does not use it.

Where Shiptrail hears ships, and where it does not

Shiptrail's positions come from receivers on land, through three sources: AISStream, which passes on what volunteers' receivers hear, and the official coastal networks of Norway (BarentsWatch) and Finland (Digitraffic). Norway's feed carries some satellite reports for Norwegian waters. Shiptrail buys no satellite data of its own.

Where it is strongest

Coasts and harbours of Europe and North AmericaVolunteers run the most receivers there, so ports in those regions can look busier than equally busy ports elsewhere.
Norwegian and Finnish watersThe official networks add to what the volunteers hear.

Where it is thin

The open oceanA ship crossing an ocean is out of range of every receiver. She is not on the map until she nears a coast, and she may be missing for days.
Coasts with few or no receiversA ship there may never have been heard. If you switch on Receiver coverage shading in the map's Settings, it shades the areas where receivers heard ships in the last hour. Water outside the shading is out of range of every receiver, so a ship there is not seen, which is not the same as not there. About explains the setting.

What the data cannot do

A dot on a map looks sure of itself. These are the things worth knowing before you rely on one.

It is not for navigationPositions are relayed, can be minutes old and cover only the waters receivers hear. Use official charts and the ship's own equipment.
A position can be minutes oldQuote a position with the time beside it. A ship in weak coverage, or a small boat, reports less often.
A ship can be out of rangeShe leaves the map 3 hours after her last report if she was moving and 6 hours if she was stopped. Her page stays and says when she was last heard.
Not every boat transmitsA boat with no transponder cannot be seen, and a transponder can be switched off. What a crew types in, such as a destination, can be wrong.
It follows ships, not what is aboardNo cargo, no containers and no people.

Questions people ask

How can I track a ship live for free?: Open shiptrail.io, type the ship's name, MMSI number, IMO number or call sign into the search box and pick her from the list. It is free, with no account to make. The map shows the ships that radio receivers on land can hear.
How do I find where a ship is right now?: Search for her on the map. Her card shows her last reported position, speed and course, and her page gives the time of her last report. If she is not on the map, she has most likely sailed out of range or switched her transponder off: Shiptrail drops a ship 3 hours after her last report if she was moving, 6 if she was stopped. Her page, if she has one, says when she was last heard.
What is AIS?: The Automatic Identification System: a radio transponder that broadcasts a ship's name, position, speed, course and destination so that other ships and stations on shore can see her. What ship tracking is, above, says more.
What is the difference between an MMSI and an IMO number?: An MMSI is a nine-digit radio identity set in a ship's transponder. Its first three digits show the flag, so it changes if she changes flag. An IMO number is seven digits and belongs to the ship's hull: it is never reassigned to another ship and stays the same when she changes flag. A small boat may have an MMSI and no IMO number. Either one finds a ship in the search box.
Can I track a container?: Not here. AIS is for ships, not boxes, and a container carries no transmitter. Your booking or bill of lading usually names the ship carrying it, so search for the ship's name. If you type a container number into the search box, it tells you the same.
Why can't I find my ship?: Most often she is out of range of every receiver, or has not been heard in the last year, so she has no page. If you typed an IMO or MMSI number, the box says when no ship with that number has been heard. Otherwise check the spelling against your booking: the box forgives a small typo, and it tries your words again without a title such as MV or a word such as yacht on the end.
How up to date is a position?: The map hears of a new report within seconds of Shiptrail receiving it, but a ship reports only every few seconds to a few minutes, and less often in weak coverage, so a position can be minutes old. Each page shows the time of the last report, and a mark fades the longer ago a ship was heard.
Why does a ship vanish from the map?: She leaves the map 3 hours after her last report if she was moving and 6 hours if she was stopped. Usually she has sailed out of range or her transponder is off. Her page stays and says when she was last heard.
Does Shiptrail cover the open ocean?: No. It hears ships through receivers on land, which reach about 20 to 40 nautical miles, so a ship in mid-ocean is not seen until she comes near a coast. Services that cover the open ocean buy satellite data, which Shiptrail does not.
Can I use it to navigate?: No. Positions are relayed, can be minutes old and cover only part of the sea. Use official charts and the ship's own equipment.
Can I track a yacht, a fishing boat or a naval ship?: Only if she has an AIS transmitter that is switched on and within range of a receiver. A boat that carries one by choice shows up like any ship, and one that does not cannot be seen, so a boat missing from the map is not necessarily missing from the sea.
Is there an app?: There is no app to install. Shiptrail works in the browser, and on a phone you can add it to the Home Screen so that it opens like an app. About has the steps.

Data sources and credits

Ship positions

AISStream, which relays what volunteer receivers hear.
Norwegian waters: Data delivered by BarentsWatch, collected by the Norwegian Coastal Administration, under the Norwegian Licence for Open Government Data (NLOD) 2.0.
Finnish waters: Source: Fintraffic / digitraffic.fi, license CC 4.0 BY.

The rest

Photographs: Wikimedia Commons, each credited to its author under its licence. Ship details: Wikidata and the US Coast Guard.
The map, the weather, the charts and the type are credited on About.