So on a boat I understand that against galvanic corrosion you really want a galvanic isolator like the VDI-16. (assuming a full on isolation transformer is too much for footprint and budget)
But how does this sit with inspection and testing, specifically in UK. A normal test rig for earth resistance will not work, as it would not be able to deal with the double-diode 1.2V threshold.
I am assuming inspectors know about this, and it is allowed. But does anyone have hands-on experience on how such an inspection would go? Is grounding the hull, though doubtless good for the RCD to work, even required on boats, or just a good idea many people do.