Even in the summer, a thunderstorm is just around the corner. It is not uncommon for docked boats to catch on fire in what at first appears to be a ‘mysterious way’, and is often discovered to be caused by a bolt of lightning. We asked Daniele Menegatti from Technautica, a leading company specialized in on-board electronic equipment, for some advice on how to avoid lightning striking our boat, and all its consequences. This is what he told us.

“Seeing how often these meteorological phenomena occur, it is important to take a moment to talk about protection systems against lightning, damage which is often not covered by insurance policies.

“Very few shipyards building pleasure boats take this problem into consideration (on pleasure boats, protection systems are mandatory through regulations, and are not always installed correctly). There is a series of simple expedients that can help improve the safety of your boat, all those aboard, and protect your equipment.

“Lightning bolts carry large amounts of energy; they can provoke surges in electrical lines even a dozen metres from their epicentre. You can create an efficient grounding system by placing the lightning rod in the highest point on the yacht (preferably in the centre, to have an adequate discharge area), connected to a copper plate (non porous) external to the hull under the waterline, with a 30 mm conduction cable cabled in the most vertical manner possible. We also suggest connecting the pushpits to the plate.

“In sailboats (with aluminum masts) the rod should be placed at the tip of the mast with an electric connection to the bulb. If the mast is in carbon you must cable a conductor inside the mast from the lightning rod to the bulb, as carbon is not a homogeneous conductor.

“You should also place surge protectors on electric lines (SPD) and batteries.

“Even with adequate protection, if lightning strikes the boat directly it is difficult to save your electronic devices; in this case you you can extend the application of surge protection devices (with grounding) close to the electrical source of the equipment needing protection. There are also specific protection devices for coaxial antennas.”

3 September 2013