ShiptrailLive map

Replaying a voyage

Watch a finished voyage again, from the port she left to the port she reached, or see the ships that came and went in a harbour over the last day.

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The wake of a ferry spreading behind her stern on a grey sea, the mountains of the Lofoten Islands on the horizon
Gerd Eichmann, CC BY 4.0

The short answer

Open a ship's page and look under Recent voyages. A finished voyage there has a Replay button: press it, and the live map plays her voyage again, from the port she left to the port she reached, as fast or as slow as you like. To watch a harbour instead, zoom the map in close and press Replay this area, which plays the last hour, or up to the last 24 hours, of the ships heard there.

Replay is free, like the rest of Shiptrail, and shows only what receivers heard. It reaches back up to 30 days.

How to replay a ship's voyage

  1. Open her pageFind her with the search box on the live map and press Full ship details on her card, or go straight to her page if you have its address. QUEEN MARY 2 is at shiptrail.io/vessel/310627000-queen-mary-2, for example. How to track a ship says more about finding one.
  2. Find the voyage under Recent voyagesRecent voyages lists the port she is in or last left, then each voyage from one port to the next, newest first, with when she left, when she arrived and how long it took. A voyage that can be played has a Replay button beside it, or under it on a phone. The first 5 show, and Show the rest opens the others.
  3. Press ReplayThe live map opens on her alone and starts to play her voyage, at a speed that plays most voyages in about 2 minutes. The top bar says Replay, not live, and a frame round the map is there to remind you that what you see is not now. Her card gives the time being shown, with her speed and course at that moment.
  4. Play, pause and move through itThe panel at the bottom has play and pause, a slider for the time, and the speeds: 20×, 60×, 200×, 600× and 2000×. Follow her (Follow on a phone) keeps her in the middle of the map. On a computer, Space or K plays and pauses, the arrow keys move the slider a minute at a time, Home and End go to either end, minus and plus change the speed, and F follows her.
  5. Share it, or go back to liveThe share button (Share on a phone) copies a link to the replay, which you can send to someone. Back to live (Live on a phone), Escape or your browser's Back button puts the live map back as you left it.

Replaying a harbour

To see the comings and goings of a whole harbour or strait, zoom the live map in until a few quays fill the screen: zoom 12 or more, the first number after map= in the map's address. A Replay this area button appears at the bottom left, or Replay on a narrow screen. Press it and the map plays the last hour of the ships heard in the area in view, at 60 times real speed, each from the first time she was heard there.

Last, in the panel, lets you choose 1, 3, 6, 12 or 24 hours. Tap a ship to open her card and see the line she took, and share a replay as you would a voyage. A link to an area replay keeps working for 24 hours; after that it opens the same place and offers its last hour. The mouth of the Maas at Rotterdam is a busy place to try.

A very busy area may hold fewer hours than you chose, and the panel says how many. When many people replay areas at the same moment, the map asks you to try again in a minute and stays live.

What a replay can and cannot show

  • Only what was heardA ship is drawn where receivers heard her. When two of her reports are more than 20 minutes and 300 metres apart, nobody knows the way she went in between, so that stretch is a dashed straight line, the slider is hatched there and her card says how long she was not heard. A stretch not heard for over an hour plays 10 times faster, so a crossing out of range does not keep you waiting. Why a ship disappears says why a ship goes unheard.
  • Up to 30 days backHer positions are kept for up to 30 days, so a voyage that left longer ago than that, or one no track was kept for, has no Replay button.
  • Voyages of up to 21 daysA longer voyage has no Replay button. Tugs and pilot boats have no Recent voyages at all, since their trips are short moves between berths.
  • Areas reach back 24 hoursA harbour can be replayed over the last day, and no further.
  • Her ports are Shiptrail's readingA voyage runs from one stop in a port to the next, worked out from where she lay stopped, so a port is the one nearest her, not her berth.
  • Not for navigationA replay is for looking back at a voyage, never for planning one.

Questions people ask

Can I see where a ship has been?
Yes, for her finished voyages of up to 30 days back: each one with a Replay button on her page plays on the map. Her page's small map also draws her last 24 hours as a line.
How far back does a ship's history go?
Up to 30 days for her voyages. A harbour replay reaches back 24 hours.
Why is part of the voyage a dashed line?
No receiver heard her there. Shiptrail draws a straight, dashed line between the two reports it has, because it does not know the way she took, and her card says how long she was not heard.
Why is there no Replay button on a voyage?
The voyage left more than 30 days ago, or it took longer than 21 days, or no track was kept for it. A tug or a pilot boat has no Recent voyages to replay.
Is replay free?
Yes, like the rest of Shiptrail, with no account to make and nothing to install. How to track a ship is the place to start.