Why are battery terminals and the battery master switch particularly prone to problems in a marine environment, compared to the same components on a road vehicle?

A. Marine electrical components are actually more resistant to corrosion than automotive ones

B. The combination of salt air, humidity, and vibration accelerates corrosion at electrical connections far faster than in a typical land environment — a loose or corroded connection can cause intermittent faults, voltage drop, or complete failure right when equipment is needed most

C. Corrosion only affects the battery casing itself, never the terminals or connections

D. This is only a concern for boats kept permanently in salt water, never for boats on a mooring or in a marina

A. Galvanic corrosion only occurs above the waterline, so anodes are purely decorative

B. When two dissimilar metals are both immersed in an electrolyte like seawater and electrically connected, a small current flows and the more reactive metal corrodes preferentially — a sacrificial anode is deliberately made of an even more reactive metal so it corrodes first, protecting the more valuable fittings (propeller, shaft, skin fittings) instead

C. Galvanic corrosion is entirely prevented simply by using stainless steel fittings throughout

D. Anodes are fitted only to prevent osmosis in GRP hulls

A. A bonding system is purely cosmetic trim connecting different metal fittings

B. A bonding system electrically connects underwater metal fittings (skin fittings, prop shaft, rudder stock etc.) together and typically to the sacrificial anode, so galvanic and stray-current corrosion is directed toward the anode rather than eating away at whichever fitting happens to be the most reactive metal on board

C. Bonding refers only to how the hull and deck mouldings are joined during construction

D. Bonding systems are only fitted to steel-hulled vessels