How to survive storms at sea

[Originally published in the May 2021 issue of SKI-BOAT magazine]

By Mike Telleira in association with SKI-BOAT magazine

SOUTH Africa’s rugged terrain and very hot summer months make it conducive to violent late afternoon thunder and lightning storms. The majority of South Africans have become accustomed to these and, to a degree, have become complacent about them, even though we watch in awe from the safety of our homes.
When we’re on our boats — be they at sea or on the country’s inland waters — the “safety at home” scenario takes on an entirely different and dangerous perspective. Gone are the lightning strike earthing systems of our house that conduct direct or indirect strikes to earth, or, if one is in a motor vehicle, the metal Faraday Cage of the vehicle’s body which insulates the occupants therein. A boat on the water, and its occupants, are literally sitting ducks. Those South African ski-boaters who have endured a violent electrical storm whilst out at sea will confirm how incredibly frightening it is.
Those of us who mostly use our craft on the ocean tend to miss the ferocity of thunder and lightning activity which, along our inshore coastline, takes place largely in the late afternoon into early evening when the vast majority of offshore ski-boats are back on the beach. However, those who fish at night, and especially the anglers who fish on upcountry inland waters and go for booze cruises in the late afternoon and early evening, are at substantial risk.
Mike Telleira who writes for the American Boating Safety Magazine — a sister magazine to Marlin and Sportfishing — willingly shared with us his findings on the subject and the numerous strategies for surviving lightning strikes while boating.
Powerful, dangerous, highly unpredictable — all are common descriptions of lightning. A direct strike that only results in ringing ears and a few roasted electronics would be considered lucky. Unlucky would be thru-hulls blown out, a sunk boat or worse – possibly serious injury or death.
Many power boaters like to think they’ve got the speed to simply outrun or get out of the way of thunderstorms, or they figure they’re safe if they only go boating when it’s clear and sunny. This attitude is aided by the low odds of a boat being struck by lightning, which BoatU.S. pegs at about 1 out of 1 000 boats in any given year. No worries, right mate?
Wrong. Engines can malfunction or run out of fuel, big storms can leave little to no room to escape, and bright and sunny mornings can quickly turn dark and threatening in the afternoon. If yours is the only boat in the area during a lightning storm, the odds of being stuck go way up, leaving you and your crew vulnerable to millions of volts raining down from the skies.
Lightning protection begins with being informed and being prepared to take action in the event of a thunderstorm or actual strike. While manufacturers can build in a degree of protection, there are several things boaters should know and do to minimise the chance for injury and damage.
A strategy of only boating on sunny, cloudless days may work well in some places, but in high risk areas like most of South Africa, this greatly curtails one’s opportunities to go boating.
Boaters should, of course, track VHF, internet and television weather reports and make responsible decisions about whether to go boating depending on the likelihood of storms. Short-term forecasts can actually be pretty good at predicting bigger storms, but small, localised storms might not be reported. This is when it’s very handy to know how to read the weather yourself.
Lightning strikes typically occur in the afternoon. A towering build-up of puffy, cotton white clouds that rises to the customary flat “anvil” top is a good indication that you should clear the water and seek shelter — or move out of the storm’s path if possible. That’s if the storm is at least some way off in the distance.
Most storms are about 15 miles in diameter and can build to dangerous levels in less than 30 minutes. If lightning and thunder are present, just count the seconds between the lightning and corresponding thunder, then divide by five — this will provide a rough estimate of how many miles away the storm is.
A storm that builds directly overhead might be less obvious until those pretty white clouds that were providing some nice shade moments ago turn a threatening hue of gray and start to dump rain and blow wind or, worse yet, boom with thunder and lightning that are right on top of each other. Now is the time for a mad dash to the dock and shelter if there’s any close by. Like our National Weather Service says: “When Thunder Roars, Go Indoors!”
If you’re out on open water or too far from shore and shelter, it’s time to hunker down and ride it out.

Boaters who have been struck by lightning often begin their stories with: “I was caught in this storm…” before they share their miraculous or harrowing tales of survival and destruction. Even though getting caught in a storm is not always avoidable, there’s still plenty that can be done to minimise the chance of a strike and reduce injury and damage if there is a strike.
We all learn at school that lightning seeks the highest point, and on the water that’s the top of the boat — typically a mast, antenna, bimini or even the tallest person in an open boat. If possible, find a protected area out of the wind and drop anchor. If the boat has an enclosed cabin, people should be directed to go inside and stay well away from metal objects, electrical outlets and appliances. It’s a good idea to have life jackets handy too. Sideflashes can jump from metal objects to other objects — even bodies — as they seek a path to the water.
Lowering antennas, towers, fishing poles and outriggers is also advised, unless it’s part of a designated lightning protection system (see sidebar). Some boaters also like to disconnect the connections and power leads to their antennas and other electronics, which are often damaged or destroyed during a strike or near strike.
Under no circumstances should the VHF radio be used during an electrical storm unless it’s an emergency. Handheld radios are okay. Also be careful not to grab two metal objects, like a metal steering wheel and metal railing; that can be a deadly spot to be in if there’s a strike. Some boaters opt to steer with a wooden spoon and keep their other hand in a pocket if they’re forced to man the helm during a storm.
An open boat like a ski-boat is the most dangerous to be on during a storm. If shore is out of reach, the guidance is to drop anchor, remove all metal jewelry, put on life jackets and get low in the centre of the boat. Definitely stay out of the water — shutdown the wakeboarding or tubing, get all bodies out of the water and stow the fishing poles.
If all goes well the storm will blow past or rain itself out in 20-30 minutes. It’s best to wait at least 30 minutes after the last clap of thunder before resuming activities.

Knowing what to do in a storm and having the best lightning protection system installed on the boat is by no means a guarantee that lightning won’t strike. The immediate checklist for a direct hit is very short:
1) Check for unconscious or injured persons. If they’re moving and breathing they’ll likely be okay. Immediately begin CPR on unconscious persons if pulse and/or breathing are absent. Remember that there’s no danger of being shocked by someone just struck by lightning.
2) Have someone check the bilges for water. It’s rare, but lightning can blow out a transducer or thru-hull — or even just blow a hole in the boat. Plug the hole, get the bilge pumps running, work the bail bucket — whatever it takes to keep afloat. An emergency call on the VHF is warranted if the situation is dire. If the radio is toast, break out the flare kit.
3) If there are no injuries and no holes or major leaks below, just continue to wait it out. Once the danger has passed, check the operation of the engine and all electronics. Even a near strike can fry electronics and an electronically-controlled engine’s ECU, cutting off navigation, communication and even propulsion. Some boaters stash charged handheld VHF and GPS units and a spare engine ECU in the microwave or a tin box for this very reason.
4) Obvious damage will need to be assessed and set right. Even those lucky enough to come away completely unscathed with no apparent damage should have a professional survey done just to be sure. Minor damage to thru-hulls can result in slow leaks, and all manner of electrical wackiness can emerge — sometimes much later. It’s best to catch these issues right away and get that information to the insurance folks for coverage.

On many levels, robust insurance coverage plays a huge role in your lightning protection plan. Knowing how to avoid storms and read the weather are certainly important, being ready for action in the event of a storm or strike is crucial, and an upfront investment in lightning protection can lessen destruction. When it comes to dealing with the aftermath of a damaging strike, however, extensive lightning coverage can’t be beat.
Just take it from a luxury trawler owner who sustained more than US$1-million in damages from a strike: “Boat insurance turns out to be the best investment we have made in the past ten years!” he said. “We will never again grumble about writing a cheque for an insurance premium.”

As mentioned above, BoatU.S. gathered insurance claim data from a ten-year period and found that the odds of being struck are about 1 out of 1 000 in any given year (see below for a breakdown by boat type). Location, however, matters a great deal. Thirteen American states — places like Nebraska and Idaho — didn’t have any lightning claims, while Florida accounted for 33% of all claims and the Chesapeake Bay area accounted for 29%.
Boat Type Chances per 1 000
Multi-hull sail 9.100
Auxiliary sail 4.500
Cruiser .860
Sail only .730
Trawlers .180
Bass boat .180
Runabout/Ski-boat .120
Houseboat .110
Pontoon .030
PWC .003

A smart phone coupled with real-time NOAA lightning tracking information can make a powerful tool for avoiding storms. Some apps will even notify you if there is a strike near any of your designated areas. Do an internet search for “lightning app NOAA” — there are a number of iPhone and Android apps available. A little early warning could give you the time you need to make it back to shore and seek shelter.

Lightning protection does not stop lightning from striking. Heeding weather warnings, avoiding storms and seeking shelter are by far the best ways to avoid injury and damage. The aim of lightning protection is to minimise the likelihood of injury and damage if struck.
In its most basic form, a conventional boat lightning protection system consists of an air terminal (lightning rod) above the boat connected to a thick electrical wire that is run down to an underwater metal ground plate attached to the hull. Sometimes an antenna or flag pole serves double duty as a lightning rod. If struck, the hope is that all the dangerous current will remain within this path instead of bouncing around the inside of the boat’s wiring and metal objects seeking multiple paths to the water (which could be through a human).
The traditional guidance has been to centre a single rod above the boat and run a single wire down through the middle of the boat to the immersed ground plate underwater. Some have challenged this method saying it’s better to use multiple rods and run wires down the sides of the boat to grounding electrodes at the water’s surface. “We want to protect the boat like a building and create multiple paths to route the lightning surge around the outside of the boat instead of down through the inside,” says Dr. Ewen Thomson, founder of Marine Lightning Protection, Inc. <>. “When routed through a single conductor down the middle of the boat, the surge can still find other paths to ground through metal objects, wires and even people — especially in freshwater, which is hundreds of times more resistant to electrical flow than saltwater.”
Current National Fire Protection Association (NFPA) standards have incorporated these ideas, and the American Boat & Yacht Council (ABYC) is in the process of reevaluating its lightning protection guidance.
Some research shows that boats without a protection system do suffer more damage, and that boats struck in freshwater get it worse than boats struck in saltwater. Larger enclosed boats, trawlers, and sailboats will sometimes come with the basic conventional protection system installed. With open boats it’s typically up to the owner to carry a portable pole with attached wire and ground plate that can be deployed in a storm.
Additional steps can be taken to protect electronics, some of which are almost always damaged in a strike. Disconnecting them in a storm makes sense, but is easier said than done. Lightning arrestors, protective gaps and surge capacitors are available to protect antennas, AC equipment and DC electronics.
While some electronics protection can be DIY work, installing a permanent lightning protection system should be handled by a professional familiar with the appropriate guidelines.

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