"to keep your boat's electronics from getting zapped" is quite simple
in theory. Lightning seeks earth (ocean). If that path goes through
electronics, then electronics are damaged. Eliminate either an
incoming or outgoing path through electronics and electronics is not
damaged. That's the easy part. The hard part is identifying all those
paths.

For example, wood is a conductor. Maybe not to electricity as you
know it. But to lightning, wood (ie a church steeple) is a good
conductor to ground. Will lightning enter a radio via antenna and exit
via desktop? Maybe. This demonstrates that one does not stop or block
lightning. So that lightning does not take that path, one must provide
an alternative and shorter path to ocean.

Protection means firstmost providing lightning a more conductive and
shorter path - ie a chain from mast to ocean. Other solutions such as
faraday cage can help. But a faraday cage is often insufficient. A
first step is always provide lightning with a non-destructive, shorter
path to ocean.

If lightning does not find a path through electronics, then
electronics is not damaged. Not only must that shorter path be
conductive. It must also be shortest, no sharp bends, not inside
metallic conduit, and no wire splices - factors that otherwise can make
wire appear electrically too long.

Do not assume lightning protectors are protection. Effective
lighting protectors make a temporary connection to the ocean. No
protector will stop, block, or absorb what three miles of sky could not
stop. An effective protector simply becomes a temporary conductor -
hopefully a shortest path - to the ocean. Anything that cannot always
be connected to the ocean and operate, then uses a protector to make
that ocean connection only during a lightning strike. Effective
protectors make temporary grounding during a transient. Ineffective
protectors are easily identified: 1) have no dedicated grounding
connection, and 2) avoid all discussion about grounding. Effective
protectors use a grounding wire to connect lightning as short as
possible to the ocean.

purple_stars wrote:
i am curious what you do for lightning protection to keep your boat's
electronics from getting zapped in the middle of the big ocean. i know
you can install lightning protection into the boat, that is, basically
a lightning rod and ground plate, etc, but that wasn't really what i
was wondering. what i am curious about is do you have some kind of
procedures you go through when a storm approaches that has a lot of
crackle in it, some procedures for disconnecting sensitive electronics
or somehow disengaging them from the boat's electrical system so that
they won't suffer if the boat gets hit ? i guess that might be
non-sense since stormy times are exactly when you most rely on a lot of
those electronics but i thought i would ask. i was just curious.