NMEA 0183 - for communication between marine electronics such as echo sounder, sonars, anemometer, gyrocompass, autopilot, GNSS receivers and many other types of instruments. Defined and controlled by the National Marine Electronics Association (NMEA)
In GGA sentence there is NaiveTime https://github.com/AeroRust/nmea/blob/c7ba32e0154633ff90f3a3f5b2fe0cf19cf7ec7f/src/sentences/gga.rs#L35 NaiveTime internally uses collect_str for serialization which involves allocation so it can't be used in no_std environments.
As a remedy we can provide manual implementation of Serialize trait when no_std feature is selected.