Help! Will My Electric Boat or Car Electrocute Me If It Sinks?

As someone on the “will this thing kill me” beat, I was paying close attention when the former president of the United States recently expressed concern about electric-powered boats — apparently, the new aquatic twist on his electric car rant. “Let’s say your boat goes down and I’m sitting on top of this big powerful battery and the boat’s going down,” Donald Trump mused to a group of supporters in the landlocked state of Iowa. “Do I get electrocuted?”

Trump then dramatically upped the stakes by imagining the sinking electric boat was also being circled by a shark. “So I have a choice of electrocution or shark,” he went on. “You know what I’m going to take? Electrocution. I will take electrocution every single time.”

I wanted to find out if it was actually possible for Trump to be electrocuted and/or eaten by a shark (you know, hypothetically). It was a question that inspired many related, obsessive searches: What about if you drive an electric vehicle into a lake — would that electrocute you? Are first responders afraid to help people in submerged EVs? Would they leave you inside to die?!

Like I said, I can be a little morbid.

Below, I attempt to sort electrocution fact from electrocution fiction, with a few detours thrown in.

Everyone knows “water and electricity don’t mix,” so who are these mad scientists making electric boats?!

People have been using electricity to power their boats for over 120 years. In fact, until the high-energy storage density of oil became obvious around the turn of the century, electric boats actually enjoyed a bit of a heyday. (RIP to the electric canoe).

Moreover, if you’ve ever been on a marine vessel with any more sophistication than a rowboat, it probably had a battery and an electrical system on board, even if it wasn’t powered by an electric motor. Standard 12-volt marine batteries are used for everything from starting the main engine to running the lights, radio, or a trolling motor on board.

The modern iteration of the fully electrified boat movement is still in its relative infancy and faces some big challenges. But the short version is, we’ve been using electricity at sea for a long time and have gotten pretty good at not electrocuting ourselves. And the potential electrocution problems that do exist usually aren’t exclusive to high-voltage electric boats, but gas-powered ones as well.

Is it possible for you to be electrocuted by your electric boat if it sinks?

First of all, battery packs on electric boats are designed to be watertight — duh, because they’re on a boat. Believe it or not, electric boat makers have taken into account the fact that their products could, in a worst-case scenario, end up underwater. A spokesperson for Arc Boat Company, a flashy new player in the electric boat space, pointed me to their FAQ which explains that “our fault table — a list of possible points of failure and what to do about each one — is hundreds of lines long, meaning we’ve thought about, tested, and planned for every scenario you might encounter on and off the water.” (This seems like a job I could be good at.)

In fact, all the electric boat manufacturers I was in touch with said they meet a waterproofing standard that is either at, or just below, what is required for a submarine. The high-voltage batteries are additionally kept in “puncture-resistant shells,” so even if the boat somehow got completely mangled, the battery won’t just be openly exposed to the water.

Still, you definitely don’t want to sit on an exposed “big powerful battery,” as Trump suggests in his scenario, since you could theoretically interrupt the closed loop of a DC battery’s electrical circuit and get shocked. But just being on an electric boat that is sinking does not inherently expose you to electrocution danger.

I’ve heard about people being electrocuted while swimming in water around boats, though! What happened there?

Electric shock drowning is caused by faulty wiring at a dock or a marina leaking 120-volt alternating current into the water. That electricity can potentially kill a nearby swimmer on its own, or cause them to become incapacitated and drown.

This overwhelmingly happens in lakes and rivers, since human bodies are a better conductor of electricity than fresh water but not saltwater. “In saltwater, the human body only slows electricity down, so most of it will go around a swimmer on its way back to ground unless the swimmer grabs hold of something — like a propeller or a swim ladder — that’s electrified,” BoatUS, a marine insurance company and safety advocacy group, explains in its publication Seaworthy. “In fresh water, the current gets ‘stuck’ trying to return to its source and generates voltage gradients that will take a shortcut through the human body.”

While it’s possible that a poorly maintained electric boat charging station could cause this sort of leak, it’s not a danger exclusive to the electric boat world; gas-powered boats hooked to shore power kill people every year, as well. Regardless, this is why you should never, ever swim around boat docks, especially at lakes.

But what about Trump’s shark?

If you are worried about sea life getting electrocuted by a high-voltage shipwreck, don’t be. When a battery is underwater, its current will flow into the water between its two terminals. This is bad for the battery (it’ll cause it to rapidly discharge) but you don’t have to worry about the entire ocean or lake getting filled with charge and electrocuting everything in it; high-voltage batteries are powerful but not nearly that powerful. If a shark is in the immediate vicinity of the battery — like, trying to eat it — it might potentially get hurt, but this whole premise is also starting to get absurd with this many “what ifs” piled on top of each other. (Really, the environmental hazard of a leaking lithium battery on the seafloor is probably the greater cause for concern.)

Okay, so electric boats aren’t an enormous electrocution threat. What about EVs? What happens if I drive an EV into a lake?

You’ll have bigger problems than electrocution!

Like electric boats, EV batteries are obsessively insulated and the cars are designed with a number of fail-safes to isolate the battery in the case of an accident. Again, the people who thought up these things have already considered the worst-case scenarios. (Plus, getting sued for repeatedly electrocuting anyone who drives through a puddle is not good business).

What’s important to understand is that unlike the 12-volt batteries used in gas-powered cars, which are harmlessly grounded to the car’s large chassis, high-voltage systems in EVs use a floating ground, which helps prevent you from being electrocuted if the car becomes submerged. “It’s not grounded chassis — there is no return path for a vehicle that has been submerged to return that charge,” Joe McLaine, a safety engineer with General Motors, told me. “And if there [are] any faults or anomalies with the high voltage system, and it’s operating in normal functioning ranges, it’s going to shut off anyway.”

Is that also true of driving through a flood?

Yes — and it’s also true of driving in the rain, or washing your car, or charging in a downpour.

Trying to drive an EV through deep water is not a great idea for a number of very good reasons, but fear of electrocution isn’t one of them. The most likely scenario is that the water will cause any less-well-insulated electronic components to short out, causing the car to die — which is what happened when Motor Mythbusters tried to drive a Nissan Leaf through a water-filled trench.

Of course, gas-powered cars don’t love driving in floods, either, and there is some reason to believe that EVs might actually do better in flood conditions than their counterparts.

Yeah, about that — can I go “boat mode” in my EV?

Back in 2016, Elon Musk tweeted that the “Model S floats well enough to turn it into a boat for short periods of time.” Just searching the words “EV” or “Tesla” and “flood” or “boat mode” will lead you to tons of videos of EVs plowing through deep bodies of water.

Don’t … do this. Most flood-related deaths occur in cars, and this fact doesn’t change just because your vehicle has a plug. Additionally, just because an EV drove through a flood successfully in a short video doesn’t mean there was no lasting damage from the water (which, it should be added, isn’t covered under warranty).

I’ve heard that EVs will catch fire after they get wet. Is that true?

Florida’s State Fire Marshal’s Office reported there were at least 21 EV battery fires in the aftermath of Hurricane Ian in 2022. This is specifically a phenomenon caused by saltwater storm surge: When the car eventually dries out, the salt residue can remain behind on the battery, creating conductive “bridges” that lead to short circuits and fires.

This is still fairly rare: “The odds that your electric battery pack is on fire in Florida are about the same odds of you getting struck by lightning,” Joe Britton, the executive director of the Zero Emission Transportation Association, told Utility Drive. To be safe, FEMA recommends that any EVs flooded by saltwater be moved at least 50 feet away from any structures, other vehicles, or combustibles. And if you are expecting storm surge, move your EV preemptively to higher ground.

Tesla echoes this advice: “As with any electric vehicle, if your Tesla has been exposed to flooding, extreme weather events, or has otherwise been submerged in water (especially in salt water), treat it as if it’s been in an accident and contact your insurance company for support,” the company writes in its user manual.

Someone told me that first responders will avoid helping people in EV accidents out of fear of electrocution.

“That is not true,” McLaine, the safety engineer with General Motors, told me. McLaine is responsible for GM’s Battery Electric Vehicle First Responder Training program, which has educated over 5,000 first- and second-responders in 25 different locations across the U.S. and Canada, and is focused on dispelling some of the rumors and misinformation around electric cars.

In addition to trainings like GM’s, a growing familiarity with the thousands of EVs now on the road has also made first responders more confident when responding to bad accidents. Orange cables are used to easily identify high-voltage components, which are placed “in areas and locations in the vehicle in which first responders typically wouldn’t have access to anyway,” McLaine explained.

First responders are trained to disable the high-voltage systems in an EV just like they would snip the cut loops around a 12-volt battery in a gas-powered vehicle accident. Additionally, most manufacturers make it extremely easy to find individual emergency response guides for their vehicles online, and there are various hotlines available for first- and second-responders when EV-related questions arise.

As for first responders handling cars that have been fully or partially submerged: Pretty much all of the emergency response documents I could find stated some version of “A submerged electric vehicle does not have a high voltage potential on the metal vehicle body, and is safe to touch” (this one specifically comes from the papers for the RAV 4 EV). Though first responders need to be careful with cutting into crushed cars, there are no shocking surprises when it comes to simply handling a submerged EV.

So … would you rather be electrocuted or eaten by a shark?

Are you kidding me? Electrocution would at least be quick! Trump got that part right: In this round of “would you rather,” you should take electrocution every time.