Is An Electric Boat More Dangerous Than a Shark? The Autopian Answers

Electric vehicles, whether they be cars, trucks, or boats, are often subject to the public’s misconceptions. It’s always the way with new technology. The very nature of electric boats was the topic of a recent speech from Donald Trump. Are you safer standing on a sinking electric boat, or jumping in the water with a shark?

The speech was delivered at Trump’s rally in Nevada on Sunday. You can watch the clip on Twitter to get the full gist, but it’s a fairly straightforward question. “What would happen if the boat sank from its weight… and you’re in the boat, and you had this tremendously powerful battery… and the battery’s now underwater, and there’s a shark that’s approximately ten yards over there?” asked Trump. “Do I stay on top of the boat and get electrocuted, or do I jump over by the shark and not get electrocuted?”

So what is the answer? Should you stay with the boat, or go for the shark?

Trump: It must be because of my relationship with M.I.T., very smart, I say, what would happen if the boat sank, and you have this tremendously powerful battery, and the battery is now underwater…. Do I get electrocuted or do I jump over by the shark? pic.twitter.com/zAUkDoOBD3

— Acyn (@Acyn) June 9, 2024

Real Talk

I’ll answer this in two ways. First philosophically, then scientifically. Put another way—first with vibes, then with physics.

Let’s say you’re on your electric boat and it starts sinking. You feel the water lapping at your ankles, and you spot a shark swimming a short distance away. If you believe yourself to be at imminent risk of electrocution on the boat, you should absolutely go near the shark instead. That is, if you know you’re about to be electrocuted, that’s certain death. The shark might be nice, and may have zero interest in eating you. Thus, based on probabilities, go hang with the shark.

Of course, this assumes that staying on the boat is certain death. Science and engineering would suggest that’s not the case.

If your electric boat sinks, that really sucks. But it’s unlikely to cause you a serious electric shock. Engineers who design electric boats are smart enough to plan for this contingency. They know the boat is going to get wet. They know it might get too wet. Thus, batteries are typically well-sealed against water ingress, and heavily protected against damage.  Ultimately, the same applies to your electric car, if you end up drowning it in a lake.

Indeed, last time Trump brought this up in 2023, Heatmap did the research. Multiple electric boat manufacturers confirmed their batteries are rated to water immersion specs suitable for submariners, or close to it. Indeed, Arc Boats notes that their packs are completely watertight. Their batteries are designed to be safe during sinking. Connectors are highly rated and the company claims to have run all sorts of safety tests on worst case scenarios, including where water might come into contact with high-voltage areas.

Even if the battery was heavily damaged and suffered water ingress, that wouldn’t necessarily put you in immediate danger. If you drop a big battery into the water at the beach, for example, it doesn’t immediately electrocute every fish in the whole ocean. Fundamentally, when submerged, the electrical current wants to flow from one terminal of the battery to the other. It will take the easiest possible path through the water to do so. That’ll usually be the shortest possible distance from one terminal to the other. If you’re in the water a few feet away, the electrons aren’t going to take a hike out of the battery’s negative terminal, come and zap you, and then go back to the positive terminal. They’re going to take—quite literally—the path of least resistance.

It all comes down to the conductivity of water. Salty sea water is more conductive than the human body. Thus, if the battery’s terminals were exposed under water, current would typically want to flow from one terminal to the other through the water itself. Unless you were right by it, you probably wouldn’t be in immediate danger. You’d want to avoid being between the terminals, lest you get in the way of the current path.

illustration: Torch

One situation where this can change slightly is in fresh water. This situation can be a little bit more dangerous. Fresh water is typically less conductive than the human body. Thus, if you’re near the battery, current may prefer to flow from one terminal to another through you instead of through the less-conductive water itself. Don’t get too close, and don’t position yourself between the terminals, and you’re probably going to be okay.

The phenomenon of getting shocked in a body of water is typically called electric shock drowning. The combination of electric shocks and water is a poor one. You might survive a given electric shock on land, but if it incapacitates you and you slip beneath the water, you can be in much greater danger.

This phenomenon has a long history— after all, electric boats are not the first to use electricity. Most powered boats have some kind of battery system on board, and many even use inverters to generate AC power for running appliances. Some boats are also capable of being hooked up to shore power—usually an AC grid feed when they’re at the dock. All of these can pose risks. Indeed, you’d be well advised never to swim at a marina—a faulty shore power system could electrocute you far more easily than a well-sealed electric boat battery.

In any case, if there’s a battery with exposed terminals in the water, you probably don’t want to sit on it or near it. But it still probably won’t pose an immediate electrocution risk. What’s most likely happening is that the battery is filling with water, which is short circuiting a ton of cells in the pack to each other, all at once. The battery will be dumping energy into the water, creating lots of bubbling as it splits the water through electrolysis. The cells will also probably release toxic gases and the battery may catch fire. That’s worth watching out for, but it’s not an electrocution risk, and it’s not immediate. As an example, we’ve seen a Tesla catch fire underwater—but nobody was electrocuted in the event.

An electric boat merely sinking doesn’t pose much electrocution risk. Just get off it and swim to safety. You obviously aren’t driving it back to the dock at this point anyway.

illustration: Torch

However, if your electric boat hits rocks or crashes with another craft, that’s more likely to be dangerous.  Your prime concern should be avoiding a damaged battery or high voltage wiring. Industry convention has this clearly marked in orange. High voltage lines could be exposed, or the battery housing could be cracked open.  A modern battery’s management system will typically shut down as much of the battery as possible in this event. However, even when “shut down” the battery still contains a great deal of energy which can be discharged through the water or damaged wiring.

In these scenarios, you want to get clear of loose wiring and battery components. If you feel any tingles, that’s a great motivator to get away from whatever’s causing it. It’s unlikely, but a broken or damaged craft could have high voltage cabling coming in contact with metal hardware, like railings or ladders. If you grabbed such a railing, you might be effectively in circuit with one terminal of the battery. if you then lowered yourself in to the water, you might form a circuit with the other terminal, and put yourself in harms way. For this reason, Formula 1 drivers are advised to jump clear of their cars in the event of a bad accident. You’d be well advised to do the same if your electric boat was badly damaged.

Ultimately, if your electric boat is merely sinking, you don’t need to flee. You’re safer near it than near a hungry shark. If your boat is badly damaged, though, you’ll want to avoid any damaged wiring or battery modules and try to jump clear of the wreck.

Still, the decision you make ultimately comes down to your own beliefs and personal preferences. For Trump, it was an easy call. “If there was a shark, or you get electrocuted?” he postulated. “I’ll take electrocution every single time. I’m not getting near the shark.” And that’s fair enough.

Image credits: Arc Boats, eDyn, Marcelo Cidrack via Unsplash license, Drawings by Lewin Day