Originally Posted by Daniel
It's in the manual; pg 107 - menu twice to access settings, then network, then 0183 output.
The piccy suggests it might not support speed. I find this very hard to believe.
Have a look at page 109.
Controls NMEA 0183 sentences used, allowing you to select the type of messages
your unit will transmit when communicating with other NMEA 0183 devices. The
default setting will work well under most conditions.
To access NMEA 0183 Output screen:
1. Select NMEA 0183 Output from the
Network menu and press enter.
2. Highlight a desired sentence and press
enter to turn it on/off.
3. To finalize changes, select OK and
Basically you enable NMEA output, set the baud rate to 4800, and enable the following sentences RMB, RMC (for the SmartCraft) and GLL (for the VHF) though I think my VHF needs RMC as well on to show speed over ground on its display.