Hi basakglkn
Radio frequency interference RFI shielding is really only necessary on non-electrically conductive material enclosers of sensitive electronic devices. The coating property that is important is electrical conductivity. Steel enclosers would not benefit from a zinc coating.
If you are thinking of shielding the internal electronics of a vessel constructed of fibre reinforced plastic or wood (non-electrical conductive structure) then Zn and Al would be effective. I have my doubts as to whether these coatings would provide any or significant "stealth" effect from being detected on radar though.
Edit:
Quote:Steel enclosers would not benefit from a zinc coating.
with respect to RFI and EMI. Obviously it would benefit from anti-corrosion