What do you do when your boat is struck by lightening? How do you recover? What items actually need replacing?
I have heard and been given so much advice, that I thought I would post our experience. Much of the advice or things I had read on the internet did not hold true in our case. I wanted to post a first hand encounter (not a friend of a friend was stuck and said this) with the facts of what damage was actually done. Of course every strike and every boat will be unique, but its not as mystical as usually posted on the internet. Lightening strikes or high voltage surges are well understood and are no different on a boat than they would be on land. So armed with a little knowledge I set out to repair our boat in the quickest and most complete manner. Here are the details of our major systems (minor systems like lights, stereo, ect are left out).
The first item I began diagnosing was the refrigerator. It would immediately kick out the breaker once switched on. At first, I thought it may be a seized compressor (maybe welded from the strike). However, the more I thought about it, the more I didn’t believe that to be true. So I pulled the fridge out and began disassembling it so I could have a good look at the cooling unit and see if I could understand how it worked. It was much simplier than I thought and I quickly realized that the most likely culprit was the motor controller itself (on our fridge its an all in one unit, motor controller, temp controller, light controller). This was further confirmed by removing the controller completely and verifying it flipped the breaker when it was disconnected from the compressor. A quick google search revealed multiple sources for the controller, so we picked a big supplier and ordered the part ($210 shipped). Once the part arrived, it took me about 20 min to put the fridge back together and test the new controller. The fridge immediately hummed back to life. Score 1.
The next order of business was the navigation lights. Not one of our navigation lights survived the strike. As I posted before, some of the bulbs actually exploded. With the surge being that powerful, we were of course worried that the wires might be damaged. Using a multimeter and some basic math we were able to confirm that most of the wires were fine and would function once we replaced the bulbs. However, 2 of the runs showed issues and indeed did not work once we tried testing with bulbs. Run 1 was up to the starboard bow light (green). It showed high resistance and the measured voltage dropped immediately after a load was introduced. This turned out to be an interesting failure as it was due to a small oversight at the factory when the boat was built. You see, the installer had decided to “zip-tie” the wire to our water fill hoses. Over the 10 years of life, those hoses moved up and down in the seas and gently bent the wire millions of times, eventually breaking it. The lightening strike blew the broken strands apart and left that wire non-functional. Unfortunately I had pulled out %80 of the run before I discovered this small break (the break was inside and looked completely normal on the outside). Oh well, I replaced the entire run and kept the good part of the wire for future repair projects. The second run that failed the test was to our stern navigation light. It had pretty much the exact same symptoms as the other light (high resistance and dropped voltage on load). This failure turned out to be where some Cuban decided that simply twisting wires together and then taping them would be good enough (at least they used tape in this instance, I found many other Cuban bodges without tape while rebuilding in Key West). Of course it had corroded and the high resistance caused the lightening to burn the wires. Once those wire issues were taken care of and the fixtures replaced where required, then new bulbs were installed and the navigation lights were working once again. Score 2
The next item was the Autopilot. This was the one thing that caused me the most stress. Even though I had a new computer as a spare, I was pretty sure multiple failures had occurred. This was confirmed when we installed the spare computer and the head unit displayed multiple errors. I was stuck buying a brand new Autopilot and all the headaches that go along with it. Of course my first instinct was to purchase a B&G autopilot to match all my other equipment. However, further research showed me that B&G was behind in their AP technology and Raymarine might be a better choice. Although a Raymarine autopilot would be harder to integrate with my B&G equipment (hey Raymarine, give up on your crappy proprietary connectors and standardize like everyone else), it would be easier to install and get running in a basic config. The Raymarine unit required no calibration and only consisted of 3 components making install very easy. So I ordered a brand new Raymarine EV200 “Autopilot in a box” and waited for it to arrive. I hoped beyond hope that the autopilot drive unit still functioned (a $2000 savings), but couldn’t test it till the new unit arrived. Once the new pilot arrived, Darrin and I set about installing it. We had the unit fully installed in about 3 hours and I was ecstatic to learn that the drive, clutch and rudder position sensor still functioned. Score 3 (although it needs and extended sea trial)
Then came the big items. All the other electronics. The chartplotter, wind, depth, AIS, VHF and such. The VHF was a “no-brainer” and I replaced it with the exact unit I lost (Standard Horizon GX1700). I also ordered the exact same antenna that was vaporized (Shakesphere squatty) and sent Rhonda up the mast to replace it. Once the antenna and VHF were replaced, we were able to confirm the external RAM mic was still functional (Yay $150 savings)
The plotter, depth and wind were also a “no-brainer” as I was super happy with my B&G stuff so I ordered exact replacements. Once the new equipment arrived, we replaced each item 1 by 1. Since B&G uses a standard CANBUS network, it was very simple to expand the network as each new item was added (we just kept moving the terminator). This allowed us to observe the network for errors as we added each new device and determine if any of the wires had been damaged. The good news was all the wires tested out fine, but EVERY sensor had been destroyed. I was quite surprised that even the depth sensor had been cooked. Another win for B&G as the depth sensor is easily replaceable while the boat is in the water (pull the old one out, push the new one in, screw the locking collar, done). While Rhonda was replacing the VHF antenna, we sent the new wind sensor up on a messenger line and she replaced it in under 2 minutes (again awesome B&G design, no screws).
AIS.. Sigh.. This was one of the big expenses. Not only would we need a new AIS unit, but we would need a new VHF splitter. Since this was such a big expense I contacted Vesper (the makers of our dead equipment) and asked it they offered a repair service. Vesper did indeed offer a repair service, but it would involve shipping all the components back to New Zealand and waiting for a quote. Then having them shipped back to where ever we might be. This would most likely take 30-45 days to complete. Rhonda and I talked it over and decided that we did not want to continue without AIS and waiting 30-45 days wasn’t an option. So we bit the bullet and ordered replacements, but went with some cheaper options. Instead of ordering the high end unit with a touchscreen and WIFI, we ordered the entry level unit that would hook up to our plotter and not have WIFI. Although we REALLY loved having WIFI and being able to see all our instruments on any tablet or laptop, we didn’t feel it was worth the $200 price tag. For $200 we could order the B&G WIFI device and have better capabilities than the Vesper provided, plus we could add that at anytime. So, since we were not going to send the dead items back I decided to take them apart and see exactly how much damage was done. Once I opened the splitter, I was in shock of the amount of damage done. The board was completely fried with tracks actually missing in places. You could see where high voltage arcs jumped between components. Unfortunately the Watchmate Vision was in the same condition. I don’t think Vesper could have repaired it even if I sent it back. Multiple boards inside had tracks completely blown off and the back of the screen has burn marks. At this point, I have sent an e-mail to Vesper asking if they would sell me a new board for the VHF splitter. That would at least give me a backup for the VHF splitter.
After those items were repaired we moved onto the engines and alternators. Although both alternators were destroyed, only the port side engines suffered other problems. This was the engine that started smoking when we were enroute. We used the multimeter and a slow process to determine that the relays had failed but the rest of the wiring seemed OK. It looks like the smoke actually came from the alternator itself. We are currently waiting on new alternators and will do more extensive tests once those arrive.
Thats about it for major systems. Of course we have repaired a long list of minor things likes LED lights, stereo, chargers (phone/tablet), WIFI, long range internet, ect… I expect we will have a few more failures in the coming months, but we will tackle them one at a time.