I think that we are talking about two issues here.
The first is that a high voltage
arc (the lightning) does not have to travel in a straight line. I assume that its path can be affected by the movement of moist air, temperature, its own inductive affect etc. so we can possible assume that from time to time lightning will do some very strange things. Anecdotal evidence would seem to support this.
I would assume that one would need to use some kind of probability analysis to evaluate strategies for dealing with a lightning strike.
The worst case seems to be that the electronics get fried, but provided basic protection is is place and the crew are below then injuries can be minimised. I do not
recall seeing a report of any crew being killed by a lightning strike, but I do have some recollection of injuries.
I found a discussion on this at :-
http://www.stewartfam.net/arlyn/lightning2.html
with a more formal aproach at :-
http://www.thomson.ece.ufl.edu/lightning/
with a more practical (insurance) aproach here :-
http://www.boatus.com/seaworthy/swlightning.asp
It does not seem to be a good idea to be in an aluminium
dinghy in the middle of a thunderstorm!
Given the number of lightning strikes that occur it would be possible that noticable damage may not occur in many cases.
The second point is the screening of electronic
gear from the electromagnetic impulse produced by the lightning strike.
Most electronic equipment is has a metal case which is grounded, and provided the lighning path is sufficiently distant from the
gear one could hope for a positive outcome.
For equipment that does not have a metal case and is not grounded I would guess that putting it in a metal box that is grounded and as far from the probable grounding path of the lightning (ie away from chainplates, mast etc,) could possibly give some protection.
However given the voltages and the energy in a major strike I do not think that complete protection would be possible.
I should note that there does appear to be a case for not grounding the mast in
trailer /sailors under some circumstances.
Members in
Florida would have a lot more practical experience than me!