help with wiring of raymarine a68 unit?

[stackz]

Ok so I finally settled on a raymarine a68 sonar unit for my 2014 sea skiff. I want to wire it up in a week or so but reading the manual it has a 12v+, negative, and an RF negative. I do not think I have an rf block on this boat. It does say if no rf ground then ground to batt negative. My question is that the rf terminal on the supplied harness is 3'. Batt ground is another 8'. Can I splice? This wire lierally looks like the standard ground and I want to tie both to the same terminal but I bought online and if I fry it then I have a $600 paperweight. Plz advice. Grammer sorry. Im on my phone.

 

[Silvertip]

Battery ground does not have to be at the negative terminal of the battery. It can be whererver you find ground which can be a ground buss at the helm, the ground terminal of any instrument, or the engine block since that is where the large negative battery cable is attached. For interference purposes however, it is best to ground at the battery and that goes for the 12 volt ground as well.