NOAA (National Oceanic and Atmospheric Administration) who are part of the US Government provide ENC chart data free of charge. This information can be downloaded and installed into ENCX.
If you only want to use unlicensed ENC data (e.g. you are only interested in US waters) then you might want to talk to us about ENCX UDE a simplified version of ENCX that only displays unlicensed ENC charts. This means no dongle which makes deployment a lot simpler.