Lightning & Sailboats, Beyond TE-4 - Ep. 124

Added: 2026-05-06

[00:00:00]So, a little bit before Christmas, I asked myself a question that I thought was going to be just one [snorts] of the many questions I had to answer for the boat work.

[00:00:10]Where should I stick this thing?

[00:00:12]Now, being an adult, this is an air terminal, more colloquially known as a lightning rod. This one in particular is a 19 mm by 150 cm, which is like 3/4 by 5-ish ft.

[00:00:29]Metric, it's so much easier. Anyways, I had this made. This is about oh 15 20 cm taller than my antenna. I had this built the size that it is because I was following TE-4, and this puts this just a little bit taller than the Shakespeare antenna that I have, the 6400R, I think it is, Galaxy [music] 6400R.

[00:00:52]Whatever. In it, it talks about the rolling sphere model of area of protection. We're going to get into all of this in the next series of videos.

[00:00:59]I'm going to keep this one relatively high level. The key thing with the rolling sphere model is that if you know where the tip of the air terminal is, you can then go out [music] some distance from the center line and do some math and determine whether whatever it is that you have there is within that area of protection.

[00:01:19]If it is, this should be what sends up the streamer, which makes contact with the step leader coming down from the cloud. When the streamer and step leader collect or connect, bam, you get a lightning strike.

[00:01:30]This being a solid chunk of aluminum, copper is better, but because the mast is made of aluminum and the mast in my boat is going to act as the primary down conductor, aluminum and aluminum don't have the risk of galvanic action and seizing and whatnot, which is why I had this made out of aluminum. The lightning strike is then directed down the mast to a bonding wire, which if I can channel my inner Chris Boden, connects to this [ __ ] thing. Now, I can hear you saying, "But Maddie, you just said that you're using >> [music] >> uh aluminum because your mast is aluminum and you don't want galvanic action, and unless aluminum comes in fun new colors, this isn't aluminum." And, [music] dear observer, you would be right. This is a chunk of C10 copper.

[00:02:12]Very heavy, very expensive chunk of C10 copper. It is 6 mm thick.

[00:02:18]It is 5 mm wide and it is 2 m long. And now my hands are dirty.

[00:02:25]At the base of the mast, I'm going to be running 4-gauge wire to bond from the base of the mast to a silica bronze through bolt that connects to this. So, the aluminum-to-copper transition already has to happen, but it's going to happen inside the boat where I can see the connection. I'm going to have it set up so that I can constantly see in case there's any corrosion ever starts to build up, I can tell and clean it and fix it before I get struck by lightning only then to find out it wasn't doing its job as properly. I don't think you can see this, so I'm probably going to do an overlay right here. When I asked myself, "Where should I mount that?" I had no clue how deep that rabbit hole was and how far down it I was going to fall. Originally, the plan had been to just do one video after I did the battery charge video last time, and when I realized "Oh, I'm going to do things a little bit different than TE-4, I should probably put together a supporting document that cited my sources." So, when I created the video, lightning is a topic that I know is going to generate some really intense feelings in my lovely nerd community. So, I wanted to have the document to show references to why I made the decisions I did. The problem is when you sit down and you try to publicly put down your points into paper, you kind of really want to make sure you know what you're talking about. And that was the start of the trip that sent me down the hole because every time I would start to figure something out, it would inevitably cause me to ask a couple more questions, and before you knew it, that's already 82 pages. This is the second attempt.

[00:04:01]That's just the table of contents.

[00:04:04]This is an attempt [music] to put into a linear narrative format a 91-page document I wrote that was me just putting down information as I learned it.

[00:04:16]That 80-some page document might make you think that I've I've done most of it. No, no. I would bring over a part and realize I needed to figure something out, and then I would be learning a little whole new bit of Oh, Christ, I've learned everything about radio physics and steam jackets and inductance and radio frequency bend radius magnetic constructive interference side flashing. I I've decided to make this video now because I realized by the time I finally finish this paper, it's probably going to be a couple more months.

[00:04:59]That little robin built a nest right above my light. She doesn't like it when I come outside. That's okay, it's my house. I'm sorry, mama, I'm not going to hurt you. Anyways, as you can see, the trees are coming into bloom, just starting to come into bloom, which means if I want to have any chance of launching this season, >> [snorts] >> this is the current state of my control board.

[00:05:26]I can't stay focused on the lightning paper.

[00:05:30]The lightning paper is going to be a huge huge thing.

[00:05:35][music] I I've got so much time into it so far. I'm definitely going to be finishing it, and honestly, at this point, [music] it's becoming less of a paper and more of a book.

[00:05:43]In it, I am going to propose several changes from what ABYC TE-4 recommends.

[00:05:50]And I'm going to make those recommendations backed by the physics and the science and the math that I have learned. Now, I don't want to go into the details of that in this video.

[00:05:59]There's so bloody much, and some of which I'm still sorting out. So, you're going to notice that the papers are not linked in the description of this video.

[00:06:07]Or rather, when the paper is finished, I will come back and append it to the description of this video. But for now, I I know the document has issues. I know that there's mistakes and problems in it, so I'm keeping it restricted to just the patrons.

[00:06:23]If you really want to see it, send me an email, [email protected], or for one buck, become a patron for one month and immediately cancel your your service and you'll get access to it.

[00:06:34]Service? Subscription. Anyways, point is, send me an email if you want to see it. [music] Let me know why you want to see it, and I'll share it with you. I'm not trying to keep it hidden and behind a paywall. I just need to make sure that anybody who sees it before it's finished clearly understands that it's not a finished product. I do want to say right from the beginning though that my criticisms of TE-4 and the reasons that I am not strictly following TE-4 are not themselves an indictment on ABYC's decisions behind the recommendations they make in TE-4.

[00:07:07]Let me explain briefly. I don't know what rationale ABYC had. I'm only making guesses. So, when I speak about what I think that they were thinking when they made the decisions that they did to go into TE-4, it is my speculation, and that's all it is. My read on it is if you're familiar with how the IIHS works, the Insurance Institute for Highway Safety, they set up a set of tests. They're not a government body. They don't mandate how car companies should build their cars, but because of insurance requirements and their car companies wanting to be able to say that they've got their top safety pick, they have driven the industry to become much much much safer.

[00:07:50]I see ABYC in general, TE-4 specifically, as the marine version of that. If you modify your boat to meet TE-4 standards, you are immediately going to be much much better off than any boat I could find that's being manufactured today. There is not a boat I could find that sells on day one already built to TE-4 standards. When you understand that I'm I'm pulling the number out of my butt, but say like 95% of sailors, if not more, modern sailors, who have private boats where they would be in a position to modify them or not modify them as they see fit, are going to be coastal sailors, weekend sailors, people who are never really going too far from land.

[00:08:35]If you get struck by lightning and you were set for TE-4 compliance, your boat is going to be [music] damaged, your electronics are going to be fried, but the chances of you getting hurt are far reduced, specifically from something called side flashing, and particularly particularly from your backstay to your wheel if you happen to be at the wheel. Tangent on a tangent.

[00:08:57]If you take nothing else from anything I do, let it be this.

[00:09:02]If you see a storm coming and you're in a position where you can't necessarily avoid the storm, consider our boats tend to run at about 6 7 8 knots, storms tend to run at 20 25 knots, you're not outrunning it. The single safest thing you can do is this.

[00:09:18]Strike your sails, put out a drogue, get below. I cannot find an instance where crew who were below on a sailboat and the sailboat was struck by lightning were hurt. However, if the storm comes and you're at the wheel and the boat gets struck by lightning, you are at a very very real risk of being killed. The details very briefly is that the unbonded backstay, its voltage is going to shoot up extremely high and extremely quick.

[00:09:48]The wheel, which is bound to ground, the water, through your rudder cables, up through the um the steering chain and into the wheel is going to be close to 0 volts if not actually 0 volts relative to Earth. Making [music] it very easy for that voltage to trigger a side flash to the wheel through your body or through the body of your crew member.

[00:10:12]The types of voltages and currents we're dealing with, those injuries are incompatible with life. This series of videos is not meant to be any kind of like a fear-mongering type of thing.

[00:10:22]The chance of a lightning strike based on I think it was about 15 years of insurance data from Geico / BoatUSI. I know I'm Canadian, but that's the public data I could find. Showed that for sailboats in the 40 to 65 ft range, your annual chance of being struck is about 1 to 1.2%. If you're in places where lightning's is very common like Florida or Lake Ontario, which is where I am, you can basically double that number.

[00:10:48]Over the course of a 5-year journey, your chances of being struck go up to if memory serves me right now about 3.2%.

[00:10:56]And if you're in a lightning-prone area, that goes up to like 5.something 6%. The chances of being struck are low, but they're not super low. There's other things we account for on our boat that have a lower occurrence from a safety perspective. I mentioned this in this opening video because one of the things I found when I was trying to figure out where to mount this was I don't worry about it. The chance of being struck by lightning is so low, just don't worry about it. You'll be fine. I understand that mentality, but I don't think it applies to people like me and I'm assuming for some of you watching this, people like you. If you get struck by lightning and you're close to the shore, you can call for assistance from the Coast Guard. Even if you're offshore, you're probably not so far offshore that you're outside the reach of someone like Matt from 103, a fantastic channel, from him coming and saving your butt with his amazing little Cormorant helicopter. For those of us who are looking to go offshore, once you get far enough offshore, you're beyond the ability for Coast Guard to rescue you even in a helicopter. That is what I am designing for because TE4 is designed to protect the humans primarily [music] and not necessarily the vessel. There's things that happen in a lightning strike that will almost certainly stricken your vessel. All of your electronics are almost certainly destroyed. Those electronics can include things like your transducer, which has electronics very very close to the water through a little 3 to 4 mm epoxy window. If you've heard of a lightning strike that led to a boat sinking, it was almost certainly because the transducer was blown out. Now, if you're on the boat and you realize that your boat is flooding, you can probably figure out where it's coming from fairly quickly if you've taken the time to know where your transducer is. You can pull it out. Most modern transducers have a flap and because they're designed to be able to be taken out and cleaned.

[00:12:53]But even if not, you can pull it out and jam a stopcock into it and [music] stem the flow. Again, I don't want to make this sound like it is a oh no, follow what I'm saying or you're going to die or your boat's going to sink. I'm very I'm being very careful in this video, in the videos that are going to follow, and in the paper that I'm writing that [music] the risks are very real.

[00:13:14]The risks at the upper end are frighteningly catastrophic, but people sail [music] and have sailed for decades without any protection and they're largely fine.

[00:13:26]>> [music] >> Insert survival bias here. The key thing with my paper and the videos that are going to come is that I'm trying to design a system such that even in a high-energy strike ABYC [music] ET4 is designed around what's called the IEC 62305 median >> [music] >> negative cloud to ground 30 kiloamp 300 megavolt strike. It's it's sort of like a laboratory standard average [music] lightning strike. They can get much more powerful than that, and the more powerful they get, especially if they're something called a positive cloud to ground strike, the devastation to the vessel can be significant sufficient that even if you do everything right, you might still be getting into your life raft. My goal is to design a lightning protection system that I will implement on Mermaid's Rest that gives me the best chance of being struck offshore, very far offshore, and having a vessel that will still be able to get to the next safe [music] port. Will there be damage? Yes. Will I lose equipment? Yes. Will I be able to make it to shore?

[00:14:28]If it's within the realm of possibility of the magnitude of the strike, I hope the answer is yes. I don't know what the next video is going to be. I don't know when the next videos are going to come out. The amount of work needed to get [music] this paper done right is far beyond what I expected. And so for me to sit here and guess how much longer it's going to take, I don't know.

[00:14:51]That was May just running by. As I feel like I've got a firm grasp on a particular component of it and I have an idea of what order I think the components should be presented in, I will be making the videos even though the paper might not be complete yet.

[00:15:06]Whenever I do finally finish the paper, I will go back and append it into the description for all of the videos. So if you're watching this or the subsequent videos and the link isn't there, I'm still working on it. And that also means that I could have made a mistake in this or future videos.

[00:15:23]If in any given video I realize I have made a mistake, I will put an update in the description. So whenever you're watching this, check to see that if in the description if there's any corrections. I I I have some real nerdery coming to play.

[00:15:40]Let me show you.

[00:15:42]As one example, I am going to be building an absolutely massive capacitor bank.

[00:15:57]I'm going to be making the conductors for this capacitor bank out of huge chunking pieces of copper, which I'm going to have to drill up and tap. Well, not tap and which I'm going to have to drill.

[00:16:08]And then I'm going to be doing my own tin electroplating, hopefully. The build is going to include things like this.

[00:16:17]This is a 47 megaohm high voltage capacitor. It was like 30 bucks on its own.

[00:16:26]The videos are going to talk about chokes. These are type 31 ferrite chokes that are going to be used to help resist the rise in current to give some of our equipment a chance to survive. I'm also going to be using some of these for noise.

[00:16:44]The lightning video is also going to have a big component of improving the VHF noise on the VHF radio.

[00:16:54]Should be able to keep our squelch much lower thanks to the lightning ground.

[00:16:59]Spoiler, the lightning ground is going to be isolated from the electrical ground, which is exactly against what TE4 says. I've got so many ferrite chokes. I had originally bought a Marinco centered bronze ground plate, >> [music] >> the large size. That was going to be the main ship electrical ground cuz obviously I'm getting rid of the engine, but instead I'm replacing it with this, which despite how black it is, >> [music] >> is actually copper. It's just very dirty. We'll talk about why that's the case and why the centered bronze is a really bad idea once you start thinking about lightning strikes. I'm going to be adding this as well. This is a secondary after lightning ground bar. This is going to allow me to address one of [music] the remaining safety concerns that TE4 doesn't address. We're going to talk about why a stainless steel prop shaft leads to explosive holes in the bottom of your boat. And it's not because the water was boiled because of the current passing down the prop shaft, which is what I thought the cause was originally. We're going to get into some pretty heavy math and physics.

[00:18:05]And generally, this is going to be a very very very nerdy side quest. As frustrating and as time-consuming as this has been to learn about, I cannot tell you how many times when I've been reading and researching this stuff, I went, "Oh, holy [ __ ] That makes sense." Or that is really cool.

[00:18:27]The time scales that are involved in a lightning strike are measured in nanoseconds and microseconds.

[00:18:34]Everything that I had learned about how electricity flows through conductors, it it all went out the window. None of it was valid anymore when you start talking about radio frequency grade waveforms that you see in a lightning strike. It has been [music] incredibly incredibly fascinating and cool.

[00:18:55]Okay. So as you saw, the trees are in bloom. I need to start really turning my focus back towards getting the boat work done. I want to launch this year if it is at all possible.

[00:19:06]One of the things I do need to sort out that might very well make it into the next video is I have to finish deciding.

[00:19:15]Now, I actually know where I'm going to mount this on the masthead. I know where I'm going to mount the antenna on the masthead, >> [music] >> but I have not yet figured out where I'm going to mount this on the masthead. That was an NMEA 2000 connected Airmar 200WX weather station. Shortly after Christmas, before I fell down this road, as you saw in the video I made earlier in the year, [music] I started being Oh, I got to the point where I could talk to this for the first time.

[00:19:43]I need to figure out how to create and parse PGN [music] packets, which are the messages used on NMEA 2000. I got the weather station so that I had something I could plug into my Raspberry Pi that has an NMEA 2000 hat on it. I need this so I can figure out how to get this to a minimum viable product where I can actually control the motion of the vessel even if I don't implement a lot of the fancier stuff. I mentioned these things right now because [music] one of the things I realized is that it is absolutely borderline impossible, certainly [music] impractical, to set it up so that the masthead can take an 85th percentile lightning strike without the [music] induced currents and voltages destroying everything on the boat. So, I'm now going to be working on [music] a modified version of the relay board that's going to use the same general circuitry. Instead of using an NMEA 2000 connection, it's going to be powered by an ESP32. The masthead is going to have a isolated power supply going to the masthead on two different 12-V rails for reasons we're going to go into later.

[00:20:50]And [music] then I'm going to have a transmitter at the helm, probably the helm might be somewhere else, that's going to send messages over wireless ethernet to control the relays to control the tricolors, the anchor light, the steaming light, and all of the stuff on the mast. This way, if the mast gets hit and everything topside is destroyed, there's basically a lightning roadblock at the base of the mast that prevents the induced currents [music] and voltages from being able to transfer over. The key thing I want I want to get across is that we have a huge amount of nerdery coming. We're going to be talking about how to save the BMS's so that we actually have power post strike, how we're going to protect the radios, how we're going to deal with the EMP pulses that come off of the induced currents, and what those can do to all of the equipment, what kind of lightning strikes where we have to accept the fact that there's just nothing practical we can do to survive it.

[00:21:46]Blah, blah, blah, blah, blah.

[00:21:48]I'm the Digital Mermaid. This has been the update of what's been going on and what is to come.

[00:21:54]>> [sighs and gasps] >> Oh, what I would do for an extra 10 hours a day.

[00:22:01]So, if you're interested in all of this lightning nerdery, uh do the subscription thingy and I'll talk to you very soon. Bye.

[00:22:10]>> [music] [music] [music] [music and singing] [music] [music] >> Need to get rid of that blue.

[00:23:14]It's a start.