Read my article on Lightning.pdf.
You won’t be killed if the mast is struck by lightning. Last year no-one in the USA was killed inside a sailboat. People were killed in fields, in open boats, and in buildings, but not inside a sailboat.
The likelihood of being struck by lightning is highest in Florida, where one out of three sailboats is damaged during its lifetime. In the Ocean you are pretty safe. In the tropics there are often thunderstorms, but not nearly as many as on the East Coast of the US.
If the boat does get struck by lightning all your electronics will be damaged, and even your engine bearings, unless you provide a safe path for the lightning from the mast head to the water. 
Read my article on Lightning.pdf.
Lightning strikes happen to airplanes every day and they are undamaged.
