Simply download the zip file below, unzip, and follow the instructions in the tutorial here.
Completed examples are also supplied in the zipfile
The zipfile contains a complete set of shapefiles generated by Reefmaster, a completed mp format chart to load into GPSMapedit, and a compiled Garmin chart ready to put onto SD card.
To make your own charts you will need GPSMapedit, the free version of Cgpsmapper
Please note the position of the chart from the images above - you will need to scroll across to this position if you load the chart into your Garmin Marine chartplotter.