Mary,
This post just shows how litle people know about lightning.
"Grounding" a boat DOES NOT prevent lightning.
On the contrary, it helps to attract it.
Lightning usually hits grounded objects like buildings, trees, antennas, LIGHTNING RODS, etc.
DUH!!!
If done correctly, grounding conducts the lightning strike to a harmless location. See: LIGHTNING RODS
As the man in the power boat found out, it isn't a matter of how high you are,
it is a matter of being the highest object in an area with a lightning strike imminent.