RupertW
Well-known member
We still use paper passage charts but I admit haven’t regularly used the rest since Cornwall to Brittany sails pre-GPS. Still always got there but fog was doubly difficult.
GPS anxiety
- Thread starter billyfish
- Start date
dunedin
Well-known member
Correction, Bill Alyard has developed AngelNav (with some input and marketing profile, I believe, from Tom C).What's a watch ?I think what Tom Cunliffe has developed is a great idea , angel something, Might stop me buying paper charts.
Runner up / highly commended in the recent British Yachting awards Winners
MontyMariner
Well-known member
I find it strange that you say that. My ES only works when the engine is off so I go by the CP contour lines and soundings and don't bother much with the ES. Tacking along the coast, I tack out at 5mtrs so have plenty of water under me, especially if you add in the tide hight. I anchor in about 2mtrs on the CP then turn on the ES if I'm feeling curious.
I have a fairly relaxed attitude to navigation, if I've been somewhere once then I can find my way back there again. I've been up and down the S coast for so many years that I can recognise where I am. X Channel, about 70nM, I set my course to arrive uptide then make any course adjustments when closing the coast. Biscay, I found pretty much the same, set course, noted by position every 6 hours then started 'navigating' near the far end.
The one bit of kit that I would really miss is the Autopilot, I hate sitting at the wheel for hours. Come to think of it, it's silly that I have two CP's but only one AH!
RupertW
Well-known member
I’m now beginning to massively disagree with my own earlier posts. I’ve fixsted on navigation as thst would barely be changed by a power loss but not thought of echo sounder (minor niggle if I know where I am on the chart ) and autopilot which would be a very big concern if it went, especially on a longer multi-day or week trip, bit as it’s still hard to see a circumstance with non-fixable electrics I’ll keep this as a thought experiment.I find it strange that you say that. My ES only works when the engine is off so I go by the CP contour lines and soundings and don't bother much with the ES. Tacking along the coast, I tack out at 5mtrs so have plenty of water under me, especially if you add in the tide hight. I anchor in about 2mtrs on the CP then turn on the ES if I'm feeling curious.
I have a fairly relaxed attitude to navigation, if I've been somewhere once then I can find my way back there again. I've been up and down the S coast for so many years that I can recognise where I am. X Channel, about 70nM, I set my course to arrive uptide then make any course adjustments when closing the coast. Biscay, I found pretty much the same, set course, noted by position every 6 hours then started 'navigating' near the far end.
The one bit of kit that I would really miss is the Autopilot, I hate sitting at the wheel for hours. Come to think of it, it's silly that I have two CP's but only one AH!
Chiara’s slave
Well-known member
I have a solution for you. You need a shallow draught boat with knock up centreboard and rudder. then you are not relisnt on an echo sounder. An extendable boathook checks depth when anchoring. There’s a picture of just such a craft not far from here.
Refueler
Well-known member
But go back to my West Africa scenario .... and you can add in Palawan Passage ... the Echo Sounder is not only a tool to read depth - but also in conjunction with DR / EP data - you can increase the accuracy of that EP .... by reading the contours vs time at speed ...
We had Transit on the Gas Ships going Brunei to Japan .... Palawan Passage is a dangerous passage utilising all skills to negotiate ... wrecks / shoals / coral reefs ... all ready to snag the stupid ...
We had one specific turn point that we used the Echo Sounder for ... and another that was both ES and radar (the radar return was iffy ... due to the low lying coastline) .... buty with ES both were surprisingly accurate. Why not turn based on SatNav ... if you haven't used Transit - then you have no idea about its position updates !!! Unlike GPS ... Transit relies on passing sats and they bunch up over about 5 - 6 days - so you get a quick succession of positions ... but then they spread out over next 5 - 6 days ... repeating the cycle ... therefore you just cannot rely on it as you do GPS. The most useful job that Magnavox did - was calculating Compass Error !!
We had Transit on the Gas Ships going Brunei to Japan .... Palawan Passage is a dangerous passage utilising all skills to negotiate ... wrecks / shoals / coral reefs ... all ready to snag the stupid ...
We had one specific turn point that we used the Echo Sounder for ... and another that was both ES and radar (the radar return was iffy ... due to the low lying coastline) .... buty with ES both were surprisingly accurate. Why not turn based on SatNav ... if you haven't used Transit - then you have no idea about its position updates !!! Unlike GPS ... Transit relies on passing sats and they bunch up over about 5 - 6 days - so you get a quick succession of positions ... but then they spread out over next 5 - 6 days ... repeating the cycle ... therefore you just cannot rely on it as you do GPS. The most useful job that Magnavox did - was calculating Compass Error !!
capnsensible
Well-known member
A friend of mine put a wind generator and solar panels on his yacht. Reason being, whilst not far from the windies on a west east, his engine starter motor solenoid fell to irreparable bits. This is a guy who, if it had been possible, would have fixed it. Starter motor damaged too. So a couple of weeks no battery charging. That's one way it can happen. And get one to spend on renewable alternatives!
GHA
Well-known member
Autopilot could be big problem, windvanes are still very popular with long distance cruisers as they're very likely fixable with some string & cable ties if they break. Dafydd Hughes forced to divert Bendigedig to Hobart - Global Solo Challenge
Position not such a big deal imho. Turn on a phone once a day or 2 for 5 minutes & should last for months.
Donw in Brasil must have been at least 25% of the boats coming up from South Africa arrived with bust engines. Not that big a deal.
It's lightning that freaks me out! Everything blown in a millisecond & compass might be miles out
RupertW
Well-known member
I used to sail my Dads triple keeler. We spent a whole summer exploring French creeks using a boat hook for depth
B27
Well-known member
The paper chart is not dead weight, GPS will give you a position, you still need a picture of what's around you, and the various packages for that are IMHO, much less robust than GPS itself.
It's good to have enough OldSkool stuff to check up on the GPS now and then.
There is a world between TPTB switching off GPS and your GPS giving a duff answer. Interference, extreme weather losses, duff software, GPS receivers, at least the consumer flavour, are not infallible.
MontyMariner
Well-known member
Neither is graph paper!
You don't need expensive charts for passage making, this is what I used pre GPS.
AntarcticPilot
Well-known member
There is a real but unlikely risk of a solar flare knocking out the satellite constellation. It doesn't matter how good your power system is on board if there are no satellites up there. There is at least one flare on record that would have fried the satellites (Carrington Flare); that happened in the 19th century and seriously affected Telegraph systems! But we've had several near misses; it's only a matter of time before we get another.
Rhylsailer99
Active member
I think I would be anxious in thick fog with no gps.
MontyMariner
Well-known member
Fog is the only time that my Radar goes on these days. Especially around Port estuaries where Fred and his mate are out drifting around doing a bit of fishing.
Airscrew
Active member
Experience is that which you gain, moments after you most need it.
GPS is that thing that you need, the moment it no longer works for you.
Never rely on GPS alone if you are without absolute certainty of knowing or finding your location without it.
There are forces out there that can, and will, disable our GPS if they wish to.
Ofcourse, I cant tell you how I know, but you should know that the threat is real.
Chance of it happening in our lifetime, probably medium to high.
Chance of it spoiling your day if you're near rocks and tide.... very high.
GPS is that thing that you need, the moment it no longer works for you.
Never rely on GPS alone if you are without absolute certainty of knowing or finding your location without it.
There are forces out there that can, and will, disable our GPS if they wish to.
Ofcourse, I cant tell you how I know, but you should know that the threat is real.
Chance of it happening in our lifetime, probably medium to high.
Chance of it spoiling your day if you're near rocks and tide.... very high.
AntarcticPilot
Well-known member
Of course, a high-altitude nuclear explosion would knock GNSS out over a wide area for days to weeks, and there is evidence of various states acquiring the ability to knock satellites out - indeed such capability has ben tested at least once.
Buck Turgidson
Well-known member
There are plenty of other things to worry about to be honest. As far as sailing is concerned I can live without GPS most of the time but I do like the benefits of AIS.
lustyd
Well-known member
My digital watch (Garmin Fenix 7) has full charts and GPS and will last a month quite happily on a charge. It has a 9 axis compass and accelerometer too. No special how to though, just flick to the compass screen and read the number
lustyd
Well-known member
No more anxious than reading stories of the Kraken, although a Kraken seems more likely at this point.
Sandy
Well-known member
Why?
Dead Reckoning and Estimated Positions are your friends. Fog will not knock out your depth sounder another clue and most light houses have fog horns for a reason.
I spent 5 days sailing up the east coast in fog. The most stressing thing was everything off the boat was in monochrome, and even the boat is white!