The iPhone's iNavX chart plotter functions are similar to your fixed-mount chart plotter, allowing you to enter, import, and export waypoints, measure bearings and distances and view your course, speed, and lat/lon position. It can automatically create a 100-point chart track that can be very useful when used in the tender to collect soundings in a channel through an uncharted area. The iPhone's WiFi link is used to transfer data to and from your on-board computer via the iNavX program's TCP/IP NMEA client feature. This allows you to display data from the yacht's instrument system on the phone, including AIS targets, when that data is available. Think about that for a moment. You now have access to your nav data in your pocket-including AIS targets-from anywhere on board.