I hope that this is a simple question to answer. My Raymarine manual
says to attach the 12V power cable's braided sheathing that surrounds
the positive and negative wires to the "boat's earth/ground". I
assume that this is for interference (RF) reasons. Is this as simple
as connecting the sheathing to the negative side of the powerbus (along
with the negative wire)? In otherwords, do the sheathing and (-) wire
both connect to the common 12V ground bus?

Thanks.