Many yachts, including Bonita, have an AIS receiver incorporated within a chart plotter so the positions of nearby merchant ships can be seen; however she does not have the additional AIS transponder to transmit her position.
Some clever techie noted that if AIS messages can be received at a shore-based radio station, the same information could be used to display ship positions live on the Internet. There are several organisations that do this, but we find MarineTraffic to be the most reliable http://www.marinetraffic.com/ais/
|Bonita from Haarlem to Amsterdam|
If you search for Bonita‑Yawl you'll see her position if she’s transmitting. If she hasn't done so for 24 hours, it will say ‘Out of Range’. It will also tell you the last time she transmitted. The picture above shows her journey a few days ago from Haarlem to Amsterdam.
You can also download MarineTraffic for an Android phone, iPhone or tablet from here. If you really want a great view on your PC or tablet, get the Google Earth 3D extension from here.
Not only can a smart phone be used to receive AIS data it can also be used to transmit it and this is how Bonita's AIS transmissions are made. As long as she’s within range of a cellular network (which is when she is in coastal waters), the phone will send out her speed, position and heading every few minutes. The messages are tiny, so the cost is negligible with a UK data plan. If she goes out of cellular range for a time, the app stores up a couple of hours worth of positions and then sends them when connected.
Transmitting AIS data makes a vessel much more visible to merchant ships which is of particular value at night or in poor visibility. So how does one set up a smart phone to transmit AIS data?
- Step 1: get yourself an MMSI number. If you have a registered VHF radio, get it from services.ofcom.org.uk/
- Step 2: Add a link to www.marinetraffic.com/ais on your PC, or load the MarineTraffic app onto an Android or Apple phone. See http://goo.gl/Dm0rD or http://goo.gl/A00fs
- Step 3: Read the background detail at marinetraffic.com/ais/iais.aspx
- Step 4 (Android Phone): go to http://goo.gl/607Pk for free app install
- Step 4 (Apple Phone): go to http://goo.gl/MbqEJ for free app install
- Step 5 Add your MMSI, decide on update frequency (affects battery use) and start transmitting…