The danger of using a simple extension cord shows up when the boater in
the next slip manages to connect the hot 120 volt wire to the water.

There are a number of classic ways in which this has been done, such as
with automotive battery chargers, home-wired extension cords, etc.

No, his breaker won't trip because the current through the water will
not rise to the 15 amp level. That unhealthy situation could exist
undetected for months. So you now place one hand on the mast and grab
the coffee pot with the other and electrocution is possible.

Of course, in a glass boat with no metal under water, you'd probably be
safe (not the case with most sailboats though).

The idea is to make sure that the boat's AC ground (connected to the
water) is at the same potential as the green grounding wire on the shore
power system. You do that by connecting the two.

Chuck

Lew Hodgett wrote:
bob wrote:

I want to add a simple shore power hook-up.

snip

Absolutely the simplest, safest, most reliable, lowest cost system is a
simple extension cord.

Plug one end into shore power, bring the other end on board and plug the
coffee pot,etc into it.

You will need a 30A/15A adapter to accept the coffee pot, etc which is a
simple item to make.

Lew