- Digital Charts of Lough Corrib


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Setting up GPSMapedit to produce Marine Charts

How the Chart is made

GPSMapedit does not have a graphics set for the Garmin extended marine objects – so it is necessary to make our own. They need to work with cGPSMapper to enable us to produce marine charts

We’ve made a custom skin file containing the extended marine objects that we use – it’s simply an edited version of an uncompiled TYP file bundled with cGPSMapper. This enables us to see objects such as Facility points and Information points – instead of just a question mark

The skin file also changes the colours of the land and water polygon objects to more accurately represent a regular nautical chart – which makes things more understandable and familiar to work with

In order to produce a Garmin chart that will display on a G2 unit it is necessary to put a “marine=B” code into the header. It has been found that some marine objects haven’t worked on the particular G2 units tested unless there is also a code “marine=y” in every objects “polish” description. This may not be true for all units, but it is better to be safe than sorry!
Garmin G2 units don’t recognise custom objects so its necessary to use the correct codes at all times, which means reconfiguring the mapping for units which recognise custom objects (if you need them), such as the GPSMap 60Csx and 276C. This is done with a TYP file. The Corrib does not have regular buoyage, but has an antiquated and unique system that predates all other systems that have been come across. Custom objects had to be created to represent these, but needed to have the chart default to IALA equivalent objects for displaying on G2 units

Soundings are coded as 0x301 objects, but with attributes set “depth =xx, marine=y”, and NO LABEL. These won’t display as numbers in gpsmapedit – which cannot display an attribute in place of a label, so the objects is reconfigured to display as a simple dot in GPSMapedit. It of course displays properly as a depth on the GPS and in Mapsource

The image to the right is the working GPSMapedit screen. Notice the custom buoyage, marine Information and Facility points
(Click for full-screen preview)

This image is the Mapsource representation of the same information, with fully functioning Information and Facility points, and depths displayed properly
(Click for full-screen preview)

More information and examples can be made available on request

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