Where are we now?

Find us now

We’ve been quite remiss in posting about our travels, for many reasons, but we will endeavour to catch up, and even this post is being composed on the iPad, in an effort to streamline the process. But this post is to provide the information about where we are now – always.

Here we are:

Click on this link

This should take you to a web page belonging to a web service that keeps a database of the position of hundreds of thousands of travelling vessels, pretty much up to the minute. You should see a map with Catharina’s position marked (if not, it’s because I have to tinker with the link). I’ll also be placing a tab on the main menu for more convenient access.

It should look something like this:

AIS

The magic is created from two systems. The first is that pretty much every large commercial ship in regulated waterways such as the EU has to carry an Automatic Identification Service (AIS) device that continuously reports the ID of the vessel and a host of information about it – it’s current status, it’s speed and destination – this is broadcast over a dedicated VHF radio channel to those ships and waterways facilities (eg bridges and locks) nearby. These devices also receive that information from nearby vessels, and it is plotted on their electronic charts so that they are aware of all the other ships around and their details.

Recent regulations have mandated that these devices have to be carried on all vessels longer than 20 m in the waterways, even pleasure craft. As Catharina is just under 20 m, she does not have to carry an AIS, but we have installed a ‘lite’ AIS type B device (cheaper, shorter range, but similar functionality to the bigger AIS-A that are mandated).

This means we have a better idea of who is around us, particularly the big commercials who present the biggest challenge – forewarned being forearmed.

So this means our position is being captured by the integrated GPS in the AIS, and reported over the airwaves every few seconds.

This is what it looks like on our navigation program. The brown is the city of Bruge, and the arrows are ships moving in the waterways. These are generally tagged with name a their speed, with the arrow giving direction. If we click on the arrow, we get more information. The diamond shapes are vessels that are moored, and at rest.

Marine Traffic

Ok, so we know where other big ships are, and they can see us, but this is limited to the VHF radio communication. However, Marine Traffic offers a service whereby some of the ground stations and a group of volunteers run software that captures the AIS data transmitted over VHF onto their computers, and relays this electronically to a central database.

Marine Traffic then wraps this in a web interface, or on mobile apps for iOS or Android, and provides a basic set of information for free. So extras are available for a subscription – but not needed to merely find a ship.

This works well, provided a VHF connected to a computer is nearby. In the more rural areas, this is often not the case, so a ship may disappear from Marine Traffic in these areas. Even then, there is an app which can send the ‘AIS-type’ data, directly from a mobile phone, over an Internet connection, to the database a ‘fake’ the AIS reception as if it was captured by one of the monitoring stations.

Now all we have to do is get some time to update the gap between what we have written, and what we have done. Not much chance today – a lovely sunny day in Bruges.

Edited with BlogPad Pro