Andrew,
Your plan is good. But I will mention two things that I have developed
as good rules.
With a rewire, install as many too many ciruits as you can fit. If you
can make or buy panels with a good deal of open space for additional
circuits - great.
Set the system up with only one(1){uno}[ichi] solitary connection per
battery post. This will not be hard to do if you plan it, and the
amount of confusion it saves is amazing.
My trailerable can carry two batteries for cruising and has an electric
start outboard. So, I got a 3/8 brass bolt to be the negative junction
and put it near the battery switch for convenience.
Matt Colie

AD wrote:
Hi,

I have recently downsized to a trailable yacht from a keelboat and I have to
re-do the electrical system ( old one doesn't work and is such a mess, I'm
starting from scratch). On my keelboat, all the negatives from batteries and
appliances( via a negative bus bar) were routed to a negative common post
and then to ground on the engine.

On the new boat, there is no external ground as such ( outboard powered and
no through hulls below waterline). Question is, do I just run a cable from
the negative bus direct to the negative battery terminal or is there a
better way to do this?

Any help appreciated.

Andrew