Wayne,

You bought a tool ?? I am concerned ... I don't think your taking the
warning provided by both Chuck and I to heart. I didn't here a "thanks
guys your right", I am meeting your concern by doing x,w,z, etc.

Instead your next post contains an incorrect reference to ABYC, and
you will buy a new tool ???

Your just buying a tool, now? No experience using it ? I know it
looks simple to use a tool to trace one wire, but preventing stray
current that can either kill or corrode (then sink your boat), has a
set of best practices behind it that are lengthy and honesty difficult
to impliment fully for a novice. In the trade, new guys spend months
working with and being double checked by experienced electricians on
AC wiring before they handle it on their own, and they still take
short cuts as it is time consuming to do it right even when you know
it all.

Chuck gave a great example of one possible outcome, there are many
more.

You want to continue to enjoy boating don't you ?
Just do the right thing and stop now.