Marine US is an iPhone/iPad universal application which gives you access to all the catalogue of nautical raster charts for USA (from NOAA Hydrographic Service material)
One of the biggest features in Marine GeoGarage service is that the charts are tied to the GeoGarage server : so no need to purchase or reload charts.
This means that the chart data will be always updated, constantly changing when NOAA releases new updated charts.
Marine US uses the embedded GPS to display the track of your boat in real-time on the multi-touch scrolling and zooming nautical chart.
Waypoint plotting with course and distance to the boat are the additional features of this basic but user-friendly mobile app.