The West Advisor article on grounding is pretty informative.
It explains how to avoid galvanic corrosion
issues. Specifically, the boat's negative supply should be treated as a dc return and not ground even though the engine
and dc negative will be connected ground at the engine
or other single
I work on land based communications
systems and grounding is a big deal. We routinely have towers that take direct hits and suffer very little damage if any. Some of the principles can be utilized on a boat to add to the protection.
First, understand that a direct hit will probably cause damage to electronics
even if grounded. The ground is primarily to keep you or someone else in proximity to the device from becoming a path to ground for a lightning surge. It will also help with EMP caused by nearby strikes that induce current
on nearby wires. This induced current
probably causes more damage than direct hits.
Second, twist the positive and negative power leads together the entire length from the supply panel to the device. If an EMP current is induced on this line, the twists may help cancel or reduce it.
Third, install surge suppressors on antenna cables
and at the shore power
supply. The rf suppressors are like barrel connectors that must be grounded to work and installed near the radio
. The shore power
protector is for surges on the commercial
power system. This might be the most common source for damaging surges. Google
whole house surge protector. Raycap is a company we use extensively for AC power protectors. It's not terribly expensive, but is very effective. You might consider protecting any other links to the outside world such as telephone, cable, dsl, etc. They make surge protectors for those links as well.