hookup lowrance gps to garmin ff help

I have a garmin 250 ff and a lowrance ifinder h20, all indications are that these units can be hooked together, I cannot seem to get them to work, does anyone have any suggestions or have tried this?

you’d have to be linking the NMEA out put from the one to the in put of the other. Remember, the one has to be the out put line, the other unit the input line. Then you have to make sure they are both set to the same speed, usually 4800 buad, 8 none and 1 for the bits.
Next question is why would you want to do this?
WarrenMN

in reading the manual you can save your waypoints from the ff instead of the display on the lowrance, but in looking a little further it may not be worth the effort..thanks