How it works: load the software onto your computer then open the application which is pretty much a map of the world. The world map is made up of many small map files that are mostly 5 degrees by 5 degrees. Many of the "map blocks" over the ocean contain no data, but show up as 1k files. select all the areas, then upload to your GPS via usb cable. You cannot load the whole world, because the number of blocks exceeds the GPS capacity. By not selecting most of the oceans, everything else should fit. I put a 2GB micro SD card in my eTrex HCx. Don't know if the map files are loaded into the GPs built in memory or the memory card. Uploading the max number of maps takes about 30 minutes. Once done, your GPS will take about 1 minute to load all the map files into main (?) memory everytime you turn your GPS on, so you will probably only want to upload the map areas you are likely to use on your trip. Map quality: Map detail is low to poor, depending on area. For instance, in a major US city, the freeways, interstates and MAJOR roads only will be shown. Coast lines are decent, and generally better than the base map. Another example: Tahiti, NO roads are shown at all. Some geographic features (a couple dozen) are shown. the topo lines are in 1000' increments, so for all practical purposes, useless. Summary: A pig in a poke. Depending where you are going it may add something useful or not. Personnally, I think a good value price for this product is about $50 US.
...
