There is only one file type that uses the .NMEA extension:
NMEA Data File
GPS file that contains data in the NMEA (National Marine Electronics Association) format; stores sentences in ASCII text that consist of latitude, longitude, and time values.
The NMEA format is used by many Marine GPS devices to transmit data from marine electronics to computers and other marine equipment. It holds data in sentence structure, with each first word, known as the data type, defining the interpretation of the rest of the sentence.
NOTE: You can import the NMEA files to .KML files with the NMEA to KML converter online.
Updated: April 11, 2015