What are they?
GTMaps are Topographical maps of New Zealand which are designed to be loaded into Garmin© Mapping GPS Units. The mapping covers the North Island, South Island, Stewart Island, and most (if not all) nearby islands. The Chatham Islands and other further offshore Islands may be available on request. The maps contain most of the information available on standard topo maps, such as roads, rivers, contours, bush cover, power lines, fences, shelter belts, sand and scree areas, and approximate hut locations.
Who uses them?
GTMaps are useful for anyone that wants to know where they are in the outdoors. Trampers (that's the New Zealand word for Hikers) Hunters, kayakers, Paraglider and Hang Glider pilots all use my maps. With GTMaps on your GPS, you can instantly work out exactly which ridge you are on - no mistakes with plotting the wrong numbers on a paper map. Instantly know how far you are from the nearest shelter, or road.
What can I use them on?
GTMaps are designed to be loaded onto any Garmin© mapping GPS. A list of compatible units is here. The maps are installed from a CD onto your PC, and from there onto your GPS unit. The maps can be used in Garmin's Mapsource program, which allows you to view the mapping on your PC. This allows you to see any downloaded tracks or waypoints from your GPS on the PC, overlaid onto your maps. The map tiles are relatively small, so that they can still be used on older Mapping units such as the Etrex Legend and Vista.
How big are the maps?
The map data is a bit over 300MB. If you have a GPS with a removable datacard, you will need at least a 512MB card to hold the maps. More details on getting a card are in the FAQ. You can find a If you have an older unit, you will only be able to load a smaller area. A 60C with 56MB will hold about 1/3 of the South Island.