ENCX UDE (unlicensed data edition) is a licensing option for people who only need unlicensed ENC/S-57 data.
For US waters, NOAA provide excellent ENC coverage free of charge.
Because UDE only supports unencrypted data it does not need a hardware or software dongle. This makes distribution of your software a lot simpler.
If this sounds useful to you then the first step is to have a look at ENCX by downloading the trial software and get in touch with us to discuss your requirements.