Turn your laptop into a chart-plotter/navigator

To guide you into that anchorage tucked away in a bay or harbour, to find that channel or river entrance, or to locate that red-hot fishing spot all you need is a low cost hand-held GPS unit such as a Garmin Etrex. These can be had for well under $100 if you look online.

You need to determine the latitude and longitude of your fishing spot or anchorage in advance and enter the position in your unit. Google maps, Google Earth or Nearmap can be used for that, or you can read the position off a suitable chart. If you have previously been to the spot, you can save it in the unit for later use by ‘marking’ the position by the press of a button.

The unit will guide you to the spot by means of an arrow. If you wish to navigate along a route, you will need to enter each turning point on the route. The track you actually travel will also be stored internally for later perusal if you so desire.

The GPS will also provide all the functions of the traditional log such as the distance traveled, the speed you are going, your average speed, maximum speed, elapsed time and so on. In addition, it will give you an accurate position of where you are and you can also read off the ‘velocity made good’ (VMG) towards a point if even if you are not sailing directly to it. The estimated time of arrival (ETA) along with a lot of other useful information will also be available. The low-cost basic units have no mapping facilities.

On the other hand, if you would like to experiment with GPS with maps, one relatively inexpensive option is to use a windows PC application that will turn your netbook or other laptop into a chartplotter/navigator. One such aplication is Oziexplorer, which can use any digital maps you may have. You can scan your own maps or charts that you already have, or purchase maps from a variety of sources. For example, the complete NSW Maritime Boating Maps for Oziexplorer can be purchased for $33. You can see examples of these below.

Android tablet showing Oziexplorer

Android smartphone with Oziexplorer

For a netbook or laptop you will need a GPS receiver. These cost about $40 online and plug into a USB port on your laptop. The GPS receiver sends a stream of position information to Oziexplorer which then plots your position on the displayed map.

Oziexplorer also has a version that works with Android or Windows mobile phones or tablets. So in effect if you already have a netbook or an Android or Windows smart phone you can have a so-called chartplotter for the cost of the Oziexplorer software plus the GPS receiver for the netbook. The cost of these devices is now in the low hundreds of dollars, so it may be within reach to purchase a unit for this job if you do not already have one. You can use any maps around that are in digital form. There is even a way to use Google or Open Street maps.

The screen shots show examples of both the Windows and Android systems. Click on the image for an enlargement.


Netbook screen shot Middle Harbour: Exploring Long Bay on the way to the Spit bridge



1 comment to Turn your laptop into a chart-plotter/navigator

  • stevospain

    I’m considering using my iPad with the iSailor app for navigation (you purchase the maps once the app is installed). I was going to mount the iPad in a waterproff casing fixed with the Railblaza deck connector. The iPad battery life is very good. Anybody have something similar or tips?