Almost everything written about boats and lightning tells you how to stay safe during a thunderstorm. Very little of it tells you what to do the next morning, when the storm has passed, your boat is sitting at the dock, and you do not know what you are dealing with.
This is that guide. It was written by a Florida marine repair facility that handles storm damage and insurance claims for a living, and it is written to be useful to you whether or not you ever call us.
First — Is the Boat Safe and Is It Floating?
Before anything else, three checks, in this order.
Check for water. The most urgent risk after a strike is not electronics, it is sinking. Lightning exiting a hull below the waterline can blow out a through-hull, a transducer, or a section of laminate. There is a documented case of a trimaran with no bonding system and non-metallic seacocks sinking after lightning exited through a transducer and the hull. Look in the bilge. Look at every through-hull and transducer you can physically reach. Look for cracked, blackened, or pitted areas around underwater fittings.
Check the bilge pumps. Then check them again, manually. Lightning routinely damages bilge pump motors, float switches, and their control circuits. A boat that took on a small amount of water and lost its bilge pump in the same event is a boat that sinks at its slip a week later while nobody is watching. If you cannot confirm the pumps work, arrange for the vessel to be watched or hauled.
Check for fire and fuel. Look for scorching, melted insulation, a burnt electrical smell, or any sign of heat damage near fuel lines, tanks, or the engine compartment. If you smell fuel or see heat damage in a fuel area, get off the boat and call for help.
If anything in those three checks concerns you, stop reading and make a phone call. Our storm line is answered 24 hours a day at 866-950-3888.
Second — Do Not Turn Everything On
This is the single most important piece of technical advice in this guide, and almost nobody gives it.
The natural instinct after a strike is to walk the boat and switch things on to see what still works. Do not do this. A damaged circuit board can short a healthy one. Energizing a whole system when part of it has been compromised can push the damage into components that came through the strike intact — and you will have converted a repairable claim into a larger one, at your own hand.
If you must test, test one system at a time, in isolation, and stop the moment something behaves oddly. Better: leave the systems off, write down what you have observed, and let the testing be done diagnostically.
Third — Document Everything, Starting Now
Your claim will be decided largely on documentation, and the best documentation is created in the first 48 hours while everything is fresh.
Write down the date, the approximate time, and the location of the storm. Note where the boat was — which marina, which slip, on the trailer, at anchor. If you or anyone nearby saw or heard the strike, write down what they saw and get their name. If a neighboring boat was also affected, note that too; it corroborates a nearby strike.
Photograph everything. The masthead and antennas. Every through-hull and transducer you can reach. The bilge. The engine compartment. The helm and every display, powered off. Any scorching, pitting, or discoloration on metal fittings. Wide shots that establish the vessel and the location, then close-ups.
Write down every symptom, even the ones that seem trivial. A chartplotter that takes longer than usual to acquire. A gauge reading that seems off. A pump that sounds different. A radio that transmits but does not receive. These small anomalies are frequently the visible edge of real damage, and the list you write in week one is far more credible than the list you reconstruct in month three.
Keep every receipt from the moment of the storm forward — haul-out, dockage, transport, diagnostics, parts, everything.
What Actually Gets Damaged
Based on what we find on the boats that come through our facility, and consistent with what the technical literature describes, damage clusters in these systems.
Engines and engine control. ECUs and ECMs, ignition and injection control, throttle and shift controls, and the sensor network throughout the engine. Engine damage often does not prevent starting. It shows up as intermittent faults, derates, drifting sensor values, and codes nobody has pulled.
Navigation and communications. GPS and chartplotters, radar, sonar and transducers, VHF, autopilot, multifunction displays, and — frequently overlooked — the NMEA 2000 network cabling itself. Yachting World’s documented case files note that anything shielded or capable of capacitance took the most damage: isolation transformers, SSB tuners, autopilots, and network cabling.
Charging and power conversion. Batteries, battery chargers, inverters, and isolation transformers. These are among the most commonly damaged components in an indirect strike.
Pumps. Bilge, livewell, washdown, and macerator pumps, along with float switches and control circuits.
Sensors and transducers. Depth, speed, temperature, tank senders, and engine sensors throughout the vessel.
Shore power and AC systems. Inlets, breakers, distribution panels, and galvanic isolators.
Bonding and grounding. The bonding system itself can be degraded by the current it carried. Since a functioning bonding system reduces damage in a future strike, its condition matters going forward as well as backward.
Standing rigging, on sailboats. Lightning current through rigging can affect the metallurgy of stainless components. This is worth a specific conversation on any struck sailboat.
Through-hulls and underwater fittings. Exit points. This is both a leak risk and a structural issue.
The fiberglass itself. Burned or heat-affected laminate, delamination, and arcing damage — particularly at exit points and around bonded metal fittings.
Fourth — Notify Your Insurer
Report the loss promptly. Give them the storm date, the vessel location, and the fact that lightning was involved. Ask what they need for a proof of loss, and ask whether they require a survey by a SAMS- or NAMS-credentialed marine surveyor — many carriers do for a damage claim of any size.
One thing worth knowing about Florida law. Fla. Stat. § 626.9541(1)(i), the Unfair Claim Settlement Practices provision, applies across all lines of insurance, including marine. Among other duties, it requires an insurer to affirm or deny coverage in writing within 30 days after proof-of-loss statements have been completed.
A caution, because incorrect information circulates widely on this point: Fla. Stat. § 627.70131 — the statute with the 7-day acknowledgment and 60-day pay-or-deny deadlines — applies by its own terms to residential property insurers and does not govern a yacht hull policy. You may also see law firm pages citing “14 days to acknowledge, 90 days to settle” for boat claims. Those figures are pre-2022 and no longer accurate. This is general information, not legal advice; for a specific claim dispute, talk to an attorney.
Fifth — Understand Scope, Estimate, and Supplement
These three words will govern how much of your loss you actually recover, and most owners hear them for the first time in the middle of a claim.
The scope of repair is the itemized inventory of everything that must be done to return the vessel to its pre-loss condition. It is the foundation. Everything downstream is arithmetic performed on the scope.
The estimate is what that scope costs.
A supplement is an additional request submitted after the initial claim has been processed, when the actual required repair exceeds the original estimate — typically because damage was missed initially, because disassembly revealed more than the surface showed, or because the initial scope understated severity.
Here is why this matters more on a lightning claim than almost any other kind. Lightning damage is disproportionately hidden, and it surfaces during disassembly and during the weeks after the event as latent failures appear. A scope written from a visual walkthrough will be wrong. Not slightly wrong — structurally incomplete, because the walkthrough cannot see the things lightning damages.
And the person who writes the scope determines what you recover.
What This Costs You, Realistically
Two things have changed the economics of a lightning claim for boat owners.
The first is deductibles. Marine lightning deductibles used to sit in the $250 to $500 range. Some policies now carry lightning deductibles as high as ten percent of hull value. On a $400,000 vessel that is $40,000 out of your pocket before the carrier pays anything, which means the accuracy of the scope is no longer a technicality.
The second is the cost of what gets damaged. Modern vessels carry far more electronics than the boats these policies were originally written for, and replacement costs have risen accordingly.
We will not publish an average repair cost, because no credible published average for marine lightning claims exists — BoatUS has not published one, and figures you may see quoted are usually homeowners lightning claim averages relabeled. What we can tell you is what drives your number.
What Lightning Damage Repair Costs — the cost drivers explained →
How Long Does This Take?
Longer than you want, and the honest answer depends almost entirely on parts availability and how cleanly the claim is scoped.
A claim that is scoped completely up front, documented well, and communicated clearly to the carrier moves at the speed of parts. A claim that is scoped from a visual inspection turns into a sequence of supplements, each requiring re-approval, each adding weeks. The single biggest lever on your timeline is the quality of the initial scope — which is the same lever that determines what you recover.
Will My Boat Be Totaled?
Sometimes, and it is worth understanding the mechanism. A constructive total loss occurs when the cost to repair the vessel exceeds — or approaches, depending on policy language — its insured value. On boats with extensive electronics packages relative to hull value, lightning can reach that threshold faster than owners expect.
Either way, a thorough scope serves you. If the boat is repairable, the scope determines what you recover. If it is a constructive total loss, the scope is what establishes that — and a scope that undercounts the damage can leave you repairing a boat that should have been settled.
Questions To Ask Any Shop Before You Let Them Touch the Boat
A well-run facility passes this list without effort.
Can you perform impedance and resistance testing on circuits, or only visual inspection? Can you scan engine control modules yourself, or do you subcontract it? Do you test systems sequentially and in isolation? Will you write the scope of repair and the estimate yourselves? Do you document and submit supplemental damage found during disassembly? Do you coordinate directly with the carrier or adjuster? Can you perform the fiberglass and structural work yourselves? Can you transport the vessel if it cannot run?
If a shop cannot do the electrical diagnostics, they cannot scope the claim. They can only scope the part of it they can see.
How We Can Help
Fiberglass Solutions provides a free storm damage inspection to any Florida boat owner who suspects lightning, wind, or water damage — including damage from a nearby strike. Our storm response hotline is answered 24 hours a day by a live person, we guarantee an inspection within 48 hours, and we serve the entire state with boat transportation available.
If we find storm-related damage, we document it, develop the scope, prepare the estimate, submit supplements for what surfaces during the work, coordinate with your carrier or adjuster, and perform the repair — fiberglass, structural, electrical, and electronics — in our own facility.
Schedule My Free InspectionCall 866-950-3888 — 24 Hours
Frequently Asked Questions
How soon after a strike should I have the boat inspected?
As soon as it is safe to do so, and ideally within the first few days. Early inspection protects the vessel from secondary damage such as an undetected bilge pump failure, and it produces documentation while the storm event is still clearly established.
Should I run the boat to see if it works?
No. A damaged circuit board can short a healthy one. Powering up systems that may be compromised can spread the damage. Test one system at a time in isolation, or leave the testing to a diagnostic inspection.
Can I file a claim if I did not see the strike?
Yes. Many valid lightning claims involve a nearby strike that nobody witnessed. What matters is documented storm activity in the area and documented damage consistent with a lightning event.
Does boat insurance cover lightning damage?
Most marine hull policies cover lightning, but terms, exclusions, and deductibles vary significantly — and lightning-specific deductibles on some policies now run as high as ten percent of hull value. Read your policy or ask your agent for the lightning deductible specifically.
What if my insurance company’s estimate is lower than the real repair cost?
That is what supplements exist for. Damage that surfaces during disassembly, or that was missed in an initial visual assessment, is documented and submitted as supplemental damage. This is routine on lightning claims specifically because so much of the damage is hidden.
Do I need a marine surveyor?
Possibly. Many carriers require a damage survey by a SAMS- or NAMS-credentialed surveyor. Ask your carrier. A survey and a diagnostic inspection serve different purposes and work well together.
My boat is in a different part of Florida. Can you still help?
Yes. We serve the entire state and provide boat transportation, including for vessels that cannot safely run under their own power.