Lightning Basics

A spectacular and beautiful natural phenomena, lightning can be devastating to a sailboat and its crew. You must ensure that you have proper "Protection" in the form of a solid lightning ground to mitigate the devastating effects of this dangerous natural phenomenon.

Lightning is unpredictable and cannot be prevented.
Lightning is one of the least understood of all natural phenomena. It is unpredictable and no one can estimate how much damage it might cause. Some sailboats that have been hit by lightning have had their hulls literally shattered while others have sustained no damage at all.

Lightning is a powerful natural electrostatic discharge produced during a thunderstorm. Lightning's abrupt electric discharge is accompanied by the emission of visible light and other forms of electromagnetic radiation. The electric current passing through the discharge channels rapidly heats and expands the air into plasma, producing acoustic shock waves or thunder in the atmosphere. The clouds act like large storage batteries that have enough energy to generate an electrical arc that can be miles in length and reach the ground. As a cloud that is negatively charged moves over the earth it causes the ground to take on a positive charge. The closer the object is, the more it gathers an opposite charge and the more intense is the electrical field around it. Tall objects such as sailboat masts on the water likely offer a very concentrated charge accumulation.

Lightning, however, can be conducted to ground if there is a low-resistance ground path for it to follow.