YB3i with NMEA

With the optional NMEA add-on the YB3i allows you to connect your own equipment and use the unit to send key NMEA data back to shore along with your tracking positions.


NMEA Enabled YB3i

As of January 2019 the 'NMEA enabled' YB3i is no longer available.

For existing users, the service will be maintained as-is but all future development for this feature has been suspended.



If you purchased your NMEA YB3i between 2015 and 2018 then the cable colours should be as follows:

Cable ColourCable Use
BrownLive (9-32v DC)
WhiteGround (0v DC)
YellowNMEA B

2019 Onwards

Cable ColourCable Use
RedLive (9-32v DC)
BlackGround (0v DC)


If in doubt, swap them out!

NMEA networks do not use RX/TX lines in the same way you would expect for other types of serial communications.

If you do not see data in your Connect NMEA Spy, try swapping the A and B wires around.

Supported Sentences

The table below lists NMEA sentence variables which can be read by the YB3i.



Table Key

Sentence (Name)
Mnemonic prefix identifier carried by the sentence.

Variable (Position)
Field position (counting left to right) of the variable of interest.

Flag (Position)
If applicable, the field position of a flag letter that modifies the interpretation of the variable value.

Precision (Decimal)
Precision to which the tracker must adjust the variable value, e.g. DP_0 is 0 decimal places.

Type (Name)
Type identifier that selects an internal set of rules for converting the variable value into its rock7 range.


MWV True or Relative flags are NOT SUPPORTED!

It is currently not possible for our NMEA Parser to handle the Relative/True flags contained within the structure of some sentences.

These sentences will be ignored by the tracker.