What is the difference between the furno gp30 & gp31

Question edited for clarity.

Page 75 of the manual refers

https://www.manualslib.com/manual/1183586/Furuno-Gp-39.html?page=75

Menu - System - Language

Menu (the U with two dots over it Umlaut) - System - Sprache

..

I have posted the Operator Manual at
http://www.offscotland.plus.com/Temp/GP30-GP35-Operator's_Manual.pdf

Use this to check out section 7-10 to make up a cable to connect to a PC to allow download of data. Then, using the manual as a reference figure out the sequence of buttons to press to get the GP31 to download the waypoint and route data to the PC. Just press the buttons and assume the display is showing the next prompt. If you know someone you has a working GP31 get them to do the sequence and write down the buttons they press. You just copy the same sequence. You will need some software on the PC to capture the data,

Is this a request for a GP31 Manual? I have posted
http://www.offscotland.plus.com/Temp/GP30-GP35-Operator's_Manual.pdf which is basically the same beast.

http://www.offscotland.plus.com/Temp/GP30-GP35-Operator's_Manual.pdf The GP30/GP31/GP32/GP35 are all similar.

You need a 7 pin NMEA cable, pn 000-154-028. Yellow is NMEA + and Green is NMEA-

TXA and TXB are the two data lines.
Confirm data present with digi meter then hook up. Try both polarities
John 847-746-0100

Make sure you installed the driver for the serial to USB adaptor cable.

Hello!
Yes, the GP31 can connect to a PC.  With the wiring harness, it has an RS-232 port, which allows it to connect to most PCs, laptops, and even most palmtop systems.
Hope this helps you out,
Ken

try
http://furuno.inforce.dk/graphics/14_Softwares/09_gps/FURUNO_GP-32_pc_connect.pdf

sounds like the problem is with the pilot. You may be expecting too much from nav mode you should check the antenna connector on the WAAS issue
on VX2, are you marking a good bottom on the sonar screen, but have no digital overlaid? never seen it, must be a BB thing