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Lots of good advice! I had an intermittent frozen plotter (somewhat less dangerous however, as the plotter would recover after a minute or two). The cause turned out to be an infinitesimally small leak in the connector on the NMEA 2K cable which took signal to/from the plotter into the pedestal and below. The leak wasn’t even visible until I disassembled the connector and then saw inside it a thin film of moisture on one pin (this was of course about the 40th thing I tried). So, not the plotter at all. The connector was supposed to be waterproof, but not quite. When I cleaned and dried it and then wrapped the whole thing in waterproof tape, the problem went away never to return. When I have time off season I will replace the cable itself. Something to check.
I have my cellphone with the Navionics app running continuously in a holder on the pedestal also – that way I can instantly check for agreement between it and the “fancy” chartplotter.
I have often had my auto GPS freeze up in the mountains. The trick in that simple case is to follow the written route instructions, which are still correct. Don’t try to restart, because you will lose the written instructions.
In the early days of chart plotters I had a long freeze-up ~ 50 miles off the east coast of the US in poor visibility (rain). Fortunately, I didn’t fully trust them back then, so I had written down lon/lat, course, and speed every 30 minutes. Dead reckoning brought me to within ~ 1/4 mile of the inlet I was looking for. I doubt I would take that precaution now, which, as you remind us, would be a mistake.
Hello Drew
In British Columbia, in high traffic areas entering airports or ferry terminals, we now have signs telling drivers to ignore the in-car GPS, look at signs and the road. Driving along at 50MPH while trying to decipher a small screen is a recipe for disaster. And yet it happens all the time.
Good tip!
I have seen firsthand too many skippers relying on just one device sooner or later running into trouble. Keeping a paper chart by the helm and plotting T D & S is simple, fun, and helps with situational awareness. Being a pilot helped develop that mindset, because redundancy is king in bad weather, whether in the air or on the sea.
I have found that following a depth contour along the coast in fog with a fathometer can be a useful adjunct to the compass and dead reckoning when electronics and radar are questionable.
Thank you all for the comments. Yes, in the modern electronic world it’s always good to have an alternative source of information. As a long time sailor I did know better and should have had more situational awareness. In a time before GPS and Loran, I would have taken more detailed action. Complacency on electronic aids is a handicap. I wonder for the safety of new sailors who don’t learn the basics of chart work (yes, remember paper charts?) with dividers and parallel rules. I still carry all that, and know how to use them, but became complacent, seduced by the technology of modern aids. A lesson learned.
The best backup for a chartplotter is another chartplotter. Just get a handheld Garmin or something in case your main plotter goes down. The backup cellphone chartplotter saved you!
Yes, redundancy is always good. But budget and space are always an issue on a small boat. This time the cell phone did save me. But it’s a lesson learned not to put complete faith in electronics and pay attention to good old fashion navigation. Thanks for reading and adding the comment.
On our boat, we have a binnacle mounted B&G Zeus 2 chartplotter but mounted in the cabin we always have an iPad operating with Navionics as a backup. I think it makes a lot of sense to have both up simultaneously.
I too have had the unfortunate experience of a chart plotter fail at just the moment in time when I needed it the most! Granted I was using the Navionics app on my cell phone, but within the cozy confines of Nantucket harbor with great signal strength I thought what could possibly go wrong? It was working flawlessly the entire time up until now (going on 10 days voyage at this point).
I departed in light/medium fog with 50-100 feet of visibility. Just enough so you could take action in case an obstacle suddenly appeared, but not enough to be able to clearly make out the next marker.
For anyone who hasn’t sailed into/out of Nantucket harbor, there is a very narrow channel one needs to navigate to get around very aggressive east and west jetties. So too do the ferries that regularly service the island. My plan was to hug the line of buoys so that the middle of the channel was clear for approaching/departing ferries.
Just as I was approaching the most critical (and narrowest) portion of this passage, where one needs to make a very aggressive turn to port when rounding the lighthouse, my Navionics app conked out. The map and my boat’s position was still being shown (thankfully) however my boat’s direction suddenly started to swing wildly, as if in any random direction.
This was not good, not good at all. Once you are in this section, there really isn’t much room, forget about when you are the only one there, now toss in the very real prospect that a (very large) ferry will be emerging from the fog trying to navigate the very same channel.
Mercifully, I was able to finally see one of the buoys, get my bearings and resume a very hair raising exit from the harbor towards the next buoy.
For the 20 minutes or so that I needed that chart plotter, it went down. I was not fully prepared for that. It was a very hair raising and tense experience. I am glad you shared your own experience regarding equipment failure of our “modern world” – one that makes you realize that you do still need to be able to read and navigate using paper and a compass.
That’s quite the story in itself Robert. Thanks for confirming that I’m not the only one out there with these sort of problems! Another lesson learned out on the water.
I would remind skippers of the col regs, which say ‘Navigate by all means available’ and the advice that a prudent skipper always has TWO independent means of establishing a possition. Ideally, if they are both electronic, then they run from different batteries. I think this story also shows the value of AIS transponders. That would have alerted both the skipper and the other vessels of the potential collision threat.