AIS receivers provide much of the coverage on the AIS Fleet map. If you have one aboard your boat or on a shore mast, it can contribute reports to that network. Those reports help update vessel positions and departure and arrival notices, including in places with little other coverage.

AIS Fleet calls each receiver you share a station, and lists them under My Stations. Sharing is free on every plan, with no limit on how many you run.

What sharing grants, before you wire anything up

Nobody but you sees the station. Other members never see its name, its position or that it exists, and nothing on AIS Fleet says which station reported a vessel.

The vessels it hears become part of what AIS Fleet knows. They are drawn for every member, they feed the departure and arrival notices, and they are included in the vessel data we license to other software and to the partners we supply, as section 3 of the Terms sets out. That permission covers reports already sent and continues if you stop sharing.

Adding a station is also what the Terms are asking you to accept, which is why you may have been asked to read them again.

Your phone as a station

If you use the AIS Fleet app on a phone that is on your boat's Wi-Fi, connect it to the receiver in the app and it becomes a station on its own. There is no separate sharing switch: a receiver the app is reading is a receiver that is contributing, and disconnecting or removing it is what stops it.

The phone appears under My Stations, named as the app named it. On the website you can rename it or remove it, and after a removal the app asks you to start sharing again before it can report. A phone row has no switch-off on the website: its switch is the connection in the app.

One phone is one station, however many receivers it is reading.

AIS Fleet on your phone covers what the app does with a receiver, including drawing what it hears directly rather than through the network.

Add a receiver

1. Open aisfleet.com/stations and sign in if asked. It is also My Stations in the account menu.
2. Choose Add a station, then A receiver, and give it a name you will recognise, such as "Masthead" or "Shore mast".
3. Choose Add receiver.

If A receiver is greyed out, direct receiver forwarding is not enabled at that time. You can still connect a receiver through the iPhone app, or write to [email protected] for help.

Point the receiver at us

The page now shows a host, a port and the protocol, UDP. Enter them in the network output settings of whatever holds your receiver's data. Any receiver, plotter, multiplexer or program that can forward NMEA 0183 sentences to a network address will do, and most can:

• An AIS receiver, a transponder or an NMEA Wi-Fi gateway with a network connection usually has a UDP output or send to setting. Enter the host and the port there.
• In OpenCPN, add a network connection of type UDP with the host and port, and turn on output for it.
• An AIS dispatcher program, or a small computer running a receiver of its own, takes the host and port as a UDP destination.

Send the AIS sentences as they come from the receiver. They begin with !AIVDM, and with !AIVDO for your own boat when the receiver is a transponder; she counts as a vessel like any other. If your GPS sentences travel on the same feed, they tell us where the receiver is listening from, and that position is shown only to you. Anything else on the feed, depth or wind for instance, is ignored.

The host and port are not secret the way a password is. Open the receiver under My Stations at any time to read them again. If you want a different port, remove the receiver and add another.

Is it working?

Each station's row tells you:

• Live, with the number of vessels heard in the last 24 hours, once data has arrived within the last ten minutes.
• Last data and a time, when it has gone quiet.
• Waiting for the first data, when nothing has arrived yet.

The page updates while it is open, and the first data usually shows within about a minute of your receiver starting to send. If it stays waiting, check the host and port, that the output is UDP rather than TCP, and that the receiver is forwarding AIS sentences. Live with a vessel count of zero means data is arriving but no vessel positions have been counted. That can happen in quiet water or when the feed contains GPS data without AIS; check the receiver's own display or output if vessels are nearby.

See what it hears on the map

Once you run a station, the map gains a Local AIS button under Traffic. It opens what all your stations are hearing right now, together:

• A switch that draws those vessels on the chart, on by default.
• A row per station saying whether it is reporting, how many vessels it has in range and how far it has heard today.
• The vessels themselves, grouped by whether they are under way or stopped, each with its distance from your nearest station, with the ones heard earlier in the day below.
• Show all on the map frames the heard boats and your stations together.

Navigation aids and other transmitters your receiver hears are listed under what they are rather than drawn as boats.

On the chart, each station is drawn as a receiver mark with a dashed ring for how far it has reached today, and the vessels your stations hear are named a zoom or two before the rest of the traffic. Tap any of them and the panel says your station heard her and when. Turn Traffic off and only what your stations hear stays, beside your own boats, which is the quickest way to watch your home waters from a shore mast. The Types panel gains a small legend for these marks, and a type you hide there hides the boats you heard too.

Two limits to keep in mind:

• A vessel drops out of the layer when your stations have not heard her for a while, so the chart never claims a boat is in range because she was this morning. She may still be on the chart as ordinary traffic, and the panel keeps her under "Heard earlier today".
• Your stations report in batches, so this view runs a little behind the receiver itself. On a phone that gap is longer for a boat sitting still, so a moored neighbour can leave "in range" while she is plainly still there. The app aboard hears the receiver directly and does not have this gap.

When a station goes quiet

A station that used to report and has sent nothing for an hour earns an e-mail, and a second one if it is still quiet after 24 hours; nothing more is sent until data resumes, when one all-clear goes out. The same notices appear under Notifications, and you choose whether you get them under Your stations in Notification settings.

A phone is not counted as quiet when the app is closed, a station you switch off is silent on purpose and gets no notice, and a station that has been silent since long before we first saw it is left alone rather than greeted with an outage.

Where the receiver listens from

A receiver with GPS sentences or its own transponder on the feed sets its position by itself. A shore receiver without GPS has none, and you can set one by hand under the gear on the station's page: it draws the receiver, and how far it reaches, on your own map. It is shown only to you, and the figures on its page do not need it.

Switching off and removing

Switch a receiver off when it is out of use for a season and on again when it returns; its record stays, and the months it was off read as time not spent hearing and as days with no boats. (A phone has no such switch: disconnect the receiver in the app.)

Remove it and its coverage record, including its statistics, goes with it, though the vessels it already reported stay on the map. Closing your account removes every station you were running.