What should crew do when a yacht is struck by lightning? This arguably freak occurrence on land is a definite hazard at sea where tall masts can make yachts the ideal target for an electrical storm. Recent cases, such as the 37.2m Vitters-built sailing yacht Ghost, whose electrical systems needed substantial repair after it was hit by a lightning storm in Florida, have brought this subject into renewed focus. The Crew Report spoke with, with Nick Smith, director of yachts, and David Sporle, consultant marine engineer, at Charles Taylor loss adjusters in London, to find out best practice for crew when lightning strikes.

What should crew do immediately on realising the yacht has been struck by a bolt?
Nick Smith: The first thing crew should do is see if they can smell smoke or if there’s smouldering going on. You can’t rely on the fire alarm system in case it’s been damaged. You should of course also check crew and guests are all safe. I have a client, although not a lightning case, where a component was overheating behind the bulkhead for up to five hours before it broke out into fire.

It sounds like the real threat of lightning is less in the moment of impact, but rather what could happen after. Can you explain more about how this affects crew?
NS: Yes, the navigation equipment is likely to be giving crazy readings after a strike, but it might not be immediate. Just because a piece of kit works today, it doesn’t mean it will tomorrow or even two months from the strike. Lightning diminishes equipment’s lifespan so it’s not a good idea to go on long voyages after lightning strikes. If you do, make sure you have paper charts or a means of securing position without electric charts. Fire is the big risk and it can develop slowly – you are more likely to be killed by fire as a result of lightning damaging equipment than by the bolt itself.

What are crew most surprised about when dealing with the fallout of a lightning strike?
David Sporle: I think they can be surprised that if the lightning has generally struck the top of a mast, being the highest point, the microwave in the galley can be affected, or part of the main engine or any of other part of the equipment throughout the yacht on the basis that everything is connected together, so it can travel anywhere.

Are there separate considerations for lightning scenarios depending on where the yacht is at time of strike? For example in dry dock for repairs, at open sea or in the marina?
DS: It may be that rather than the failure of any systems in place to protect yachts from lightning striking, it’s the fire detection and extinguishing systems that weren’t activated. On land, if people are doing repairs for example, it may be that the system is gagged to prevent it going off by accident, but that can have devastating consequences. If the yacht was not in water, there may be an issue as regards effectiveness. Lightning conductors are fitted to a vessel to protect it (copper conductors are fitted inside or outside of the mast, because copper is least resistant to electricity and is able to take the current down to the earth to dissipate it and thereby avoid collateral damage to the yacht. But if that was connected on top of mast down to a hull fitting, and the fitting was not connected to the ground, the conductor may not be effective. That is when lighting goes through something else that was connected.

NS: There are less incidents at sea or in marinas in Europe than in Florida. There are areas of Florida that act as a sort of an alleyway for lightning storms. The most important thing to consider at sea, particularly if you’re a sailing yacht with a tall mast – and masts are getting taller with the advent of larger sailing yachts to the fleet over  the next year - is to check the copper conductor is fitted,and that it’s  connected where it should be.

DS: Racing yachts are particularly light, made with carbon fibre. Some owners may be rather loathe to have this rather large copper conductor going on the outside, but if they don’t have it the mast itself will act as conductor as the highest point and be annihilated in an electrical storm.

Should crew be worried they are personally in danger when it comes to lightning strikes and storms?
NS: There are crews on yachts and lightning striking the yachts all the time. Even in a yard, it would be safer to have someone there near or on the yacht to raise the alarm. We’ve not heard of any casualties. It’s unlikely that a crewmember on a yacht is going to be effected unless they have got a lightning conductor in their hand.