1. Locate me - Press this button to center the map on yourself. When it is green, it locks on to your position, until you move the map over a certain amount. This is the North Up mode. Touch the button again and it will turn purple. This is Track Up mode and the map will rotate as you move and change your bearing.
2. Download maps - This button lets you download a section of the map by drawing a rectangle with your finger. You can load saved maps via the Saved Screen. You can download up to 10,000 tiles on the 3GS/iPod and up to 10,000 tiles on the 3G - this amounts to several hundred megabytes of maps, depending on the map type. You can download as many areas as you like subject to available space on your device. To reduce space requirements, consider limiting the max zoom level. A zoom of 15 corresponds to most Coast/Approach chart scales while 17 is the maximum zoom in detailed harbor charts.
3. Satellite Maps -Switch to a Google satellite view. In this view, you can view waypoints, but your tracks won't show up, and you can't cache these maps for offline use, due to licensing restrictions.
4. Mark waypoint - Press this button to mark waypoints and toggle POI labels - you can drop a pin in the center of the map (Drop Pin), near you (Drop Pin Near Me), or you can quickly save a position with one long touch on the map and a release at the place you'd like a waypoint. While the waypoint is in edit mode, you can drag the waypoint pin to adjust its location, enter a custom waypoint name, or adjust location by directly editing the lat/lon values.
To delete the waypoint without saving, hit cancel. To save the waypoint to your Saved table, hit Save. To save the waypoint and active distance/range/time guidance hit the Save & Guide button. In guide mode, a new info window will appear at the bottom of the map showing distance and bearing to the waypoint. Cancel Guide mode by hitting the red 'X' in the info window. Note that Guide Me does not consider water depths or other hazards - so use responsibly.
5. Layers - Use the layer button to select different available base maps and overlays. Supported base maps include EarthNC's NOAA Raster Charts, US Topographic Quad maps by myTopo, and road maps by OpenStreetMap. Overlay options include your personal, saved waypoints, the EarthNC Points of Interest, and a realtime Nexrad RADAR overlay which updates every 10 minutes. The Nexrad overlay requires an active data connection.Interacting with Points of Interest (POI's) - When POI's are enabled via the layers menu, you can click on individual icons to view additional information. If labels are off, the 1st tap will show the POI name. You can then tap on the tool (wrench) button next to the name to view additional details. Click on the Arrow button in the top right of the details window to email a waypoint or to activate Guide Me mode to that POI. Note that Guide Me does not consider water depths or other hazards - so use responsibly.