SEAiq Free is a full-featured marine navigation app. It automatically downloads all charts (both vector and raster) from NOAA and the US Army Corps of Engineers for regions of USA you select.
Other features include:
* Night color modes
* Anchor alarm
* Automatic download and display of weather (wind & isobar)
* Active Captain Interactive Cruising Guidebook
* Chart measuring tools (EBL/VRM)
* WiFi-based NMEA and AIS
* Raster charts
* Vector charts
No purchase is required in order to use SEAiq Free to view charts. All features are enabled during a 7-day evaluation period. After that, many of the feautures require purchase of an in-app upgrade.
Continued use of GPS running in the background can dramatically decrease battery life.