The map opens on a marine chart carrying the AIS traffic AIS Fleet has received, and updates while you watch. Use the controls to choose what appears, and check a vessel's last-heard time to understand how recent her position is.
What the marks mean
- Vessels are coloured by type. The categories are Sailing, Pleasure, Passenger, Cargo, Tanker, Fishing, Tug and workboat, Law Enforcement and Other, which is as fine as colours on a chart can usefully get. A vessel whose type does not fit any of the first eight is drawn as Other, which is where research ships, dredgers, pilot boats and anything unusual land.
- A moving vessel is drawn as an arrow on her course over ground, which is the direction she is actually making rather than the way her bow points. A stopped one sits quietly and is not turned at all, and the selected one carries a ring.
- A boat you have a relationship with wears her own colour: your own boat, the boats you follow and the boats on your lists, and your fleet mates. A boat can carry only one, so a fleet mate you also follow shows as one you follow, which is the stronger link of the two.
- A boat nobody has heard from in a while, but who you asked for by name, is drawn as a hollow dashed ring rather than a hull, with her age written beside her. The shape is the point: an arrow would assert a heading her fix cannot support.
Light and dark themes are in the account menu, behind the person icon.
The controls
They sit down the right-hand side, and which of them you see depends on what you have:
- Traffic is a switch for the ordinary AIS traffic, everyone who is not one of yours. Turn it off and the anonymous vessels leave the chart while the boats you follow, your fleet mates, your own boat and whatever your own receivers hear stay, which is handy when you are hunting for your rally across half a sea or saving data on a slow connection. It is remembered on the device you set it on, and the line at the bottom of the map says "Traffic off" while it is.
- Lists holds the boats you follow, sorted: Favorites, the boats you photographed, the lists you made and the lists you subscribe to, one row each with its own switch. Lists
- Fleets appears when you have a boat linked, a claim under way, an existing membership, or a plan that lets you start a fleet. You can organize a fleet on a paid plan without owning a boat. Fleets
- Local AIS appears once you run an AIS receiver of your own, and opens what your receivers are hearing right now. Share your AIS receiver
- Types is the filter and the legend at once: turn a category off to quieten the chart, and the swatches tell you what each colour means. Show all and Hide all at the top set every category at once, so watching one kind of boat is Hide all then the one you want. The panel is remembered.
- Fit track joins them while a track is drawn, and frames the whole line.
The zoom and locate buttons are on the left.
Nothing here moves your map unless you ask it to. Switching a fleet on usually changes nothing you can see, because fleets are spread across the world, so the map says what it did: how many boats it put on the chart and how many are in your view, with Show all to frame them. Jumping to one boat from a list or a roster flies to her without turning her list back on, and closing her panel puts you back in the list you came from.
The filter can never hide one of yours
A vessel on a list you have switched on, a fleet mate from a fleet you have switched on, your own boat and the vessel you have selected keep their marker whatever else you switch off, Traffic included.
A vessel your own receiver hears is ordinary traffic to the filter: hide her type and she goes with it. Her marker wears no colour for being heard by you; open Local AIS for the list, or tap her and her panel says your receiver heard her and when.
A vessel within your plan on a list you have switched on is included even outside the current view. Show all on the map or her list row takes you to her last reported position. Switching all lists containing her off removes that list marker; she can still appear as ordinary traffic or through another enabled layer. You still follow her, and the map switch does not mute her notices.
Names appear as you zoom in
Your own boat and the boat you have selected are always named. The boats you follow and your fleet mates are named wherever their names fit without piling onto each other, so a rally seen from far out is a cluster of coloured marks with a few names, and every name is there by the time you are close enough to read them. Ordinary traffic is named from coastal zooms in. The coloured pool under a mark never disappears, so you can always tell one of yours from the crowd.
Zoom decides how much is drawn
At ocean scale the map draws the larger ships only. Zoom in and the smaller vessels join, and from coastal and harbour zooms it draws everything it has. A twenty metre boat appears as you zoom in rather than being missing.
Where a view holds more traffic than the map will draw, it says the view was truncated rather than dropping the rest without telling you. Zooming in narrows the view and brings the rest back.
Why a vessel disappears
Following a link that names a vessel, from a notice or an e-mail, opens her on the chart whether or not she was drawn there already. If nothing has been heard from her for more than a day, the chart still goes to the position she last reported, draws her there while her panel is open, and says how long ago that report was. Closing her panel removes that extra marker; boats already on your map remain. If nobody has ever reported a position for her, the chart stays where it is and says so, and her panel opens on what is known about her.
The ordinary explanations, in the order they are likely, are on When something is not working. If she is a boat you follow, her row under Lists tells you which of them it is faster than the chart will.