Out of the blue - lightning protection on yachts
Around 250 instances of lightning damage are handled by Pantaenius every year - and the trend is rising. Axel zu Putlitz-Lürmann, Director of the Damage Department at Pantaenius, discuss what may be causing this concerning trend.
While the use of lightning protection systems for buildings is widespread, it is still in its infancy in recreational boating. In contrast to commercial shipping or large yachts, which are built according to class guidelines, series-produced yachts generally do not have any in-built protection. There are no binding standards or guidelines for lightning protection systems on yachts, and therefore it is the owner’s responsibility to acquire the appropriate protective devices.
"Lightning protection for a yacht is a very complex subject that requires a great deal of specialist knowledge," says Putlitz-Lürmann. "There is technical literature from the most diverse ranges, but an effective retrofitting on yachts is always difficult, complex and under most circumstances, very cost-intensive. Yachts today are better equipped than before, with extensive navigation electronics and on-board technology fitted as standard, but the investment in lightning protection is nevertheless worthwhile. While 20 years ago many owners had only basic electronic equipment on board, today yachts are stuffed with high-tech devices such as GPS, chart plotter, AIS, radar equipment, autopilot, satellite communication, radar, fishfinder, etc and, in most cases, many or even all devices are connected to each other via a bus system. In the event of a lightning strike, the lightning current can rush through the entire network and damage all devices, with disastrous consequences," explains the Pantaenius claims expert, who has already examined numerous lightning damages.
It’s not only the technical equipment at risk; structural damage to the boat, up to total loss, can also be the result. A glance at the damage statistics illustrates the problem: between 2010 and 2019, the average loss amount for lightning damage increased by around 40 per cent.
How can such a scenario be defused?
Conventional lightning protection systems work by conducting the lightning current, in the event of an impact via the standing cargo and the mast profile, into the keel, from where it reaches the water. While this is a relatively minor problem with aluminium and steel yachts due to Faraday's cage principle, it is more difficult with wooden and GRP yachts.
A simple, but rather makeshift solution is a system that consists of copper conductors and clamping devices that can be attached to the mast, shrouds and stays. The free ends of the cables are hung into the water about 1.5 metres deep, to divert the lightning. Theoretically logical, but comprehensive protection cannot be guaranteed. The behaviour of a lightning flash is very complex - it splits, strikes over and can even get back on board from the water. In addition, there is the danger of lightning damage from outside the yacht, typically via the shore power connection in the port.
Conclusion: If you are thinking about implementing an effective, comprehensive lightning protection system for your yacht, you should consult an expert both for new builds and for the retrofitting of such a system to a used boat.
Safety for life and limb should always come first: In the event of an approaching thunderstorm it is important to take the following precautions and actions:
- If possible, call at the nearest port or visit a protective bay.
- Bathers leave the water immediately
- Withdraw fishing lines
- If possible, go below deck. If you must remain on deck, do not stand and sit as low as possible with closed legs in the boat (cockpit), wearing shoes with rubber soles.
- Do not touch metal parts
- Disconnect shore power connection if in port
- Switch off the main switch; if possible disconnect the mains plug and antenna plug from electrical and electronic equipment, as well as the cable connections to receivers on the masthead.
Looking to the future
A newly developed system from the USA aims to completely prevent lightning strikes to yachts by ionizing the air at masthead height, instead of diverting the lightning current. In Europe, however, these devices are not yet available for purchase. Extensive tests are pending.