Lynn,

You are actually completely correct. - Except that my S2 has no metal
contact water when at the rest waterplane. The chainplates are
internal, the board lift gear is lifted dry, the rudder is outboard and
has gudgeons that are on the transom and the engine is raised unless it
is running.

In seven years, my outboard (that is connected to ship's power to charge
batteries) shows no electrolysis, corrosion or cavitation damage.

If it isn't in the soup, it won't cook. Electrolysis damage is a time
and EMF (think current flow) situation. There is little time available
in the case of most outboard-trailerables, even those that live in a slip.

Matt Colie A.Sloop "Bonne Ide'e) S2-7.9 #1
Lifelong Waterman, Licensed Mariner and Pathological Sailor

Lynn Coffelt wrote:

My boat does not have any metalic through hulls at all, and it doesn't
even have keel bolts. The only through hull is for the speed/log.

The bonding ground is really to prevent electrolysis by preventing a
differential potential between fittings. With an inboard you are stuck
with metal in the water - we are not.

Matt


First, I am certainly no expert in electrolysis prevention techniques,
but since there are apparently none responding, Here's my 2 cents worth:
When the outboard is in the water, there is certainly metal in the
water, and often considerable cavitation. That, along with the rudder, which
usually has an aluminum or stainless steel post is more metal. Chain plates
for shroud, back and fore stays are usually metal too? Often in or covered
with water, no? Again, no expert here.
Lynn