Originally Posted by stefano_ita
Just to know, where do you connect the ground of battery charger
and other stuff that has a metallic box that need to be grounded? (on the shore, but on the sea?to the keel's bolts?)
In many cases, the neg is connected to the engine
block and many engines are connected to (via the shaft) to the water
outside. You do not need other ground.
BUT this all depends on the boat - some are made of metals and have isolated engine
blocks, others have soft couplings and thus no connection from the engine to the water
Boats that have heavy gauge electronics
(e.g. HF radios) have special ground plates fitted to the outside of the hull
strike ground (if present) is often the keel
(ballast) itself. Note some boats have encapsulated ballasts ...