Latitude and Longitude - no more?

[RunAgroundHard]

Nothing says the speaker hasn't a clue more than when they give their position to the third decimal place of a minute of arc ...

I would not be so judgemental. If faced with giving position in an emergency and reading the Lat and Long from a machine, why would I not read out all the figures there and then?

 

[lustyd]

being able to point / know where you are on a chart, in a dynamic pilotage scenario rarely involves plotting a Lat / Long, in my experience

I think for the vast majority these days there won't be a chart or a need to point at anything. My position is where the little boat icon is on the two built in plotters, or the little triangle on my watch and handheld plotter. My phone also has Navionics and I think that's a triangle too, but been a long time since I used it. My previous positions are shown by a line, not a series of crosses. Occasionally we do a bigger or more serious passage and put some bits of paper out, but realistically this is how most people get about in 2023.

 

[RunAgroundHard]

I think for the vast majority these days there won't be a chart or a need to point at anything. My position is where the little boat icon is on the two built in plotters, or the little triangle on my watch and handheld plotter. My phone also has Navionics and I think that's a triangle too, but been a long time since I used it. My previous positions are shown by a line, not a series of crosses. Occasionally we do a bigger or more serious passage and put some bits of paper out, but realistically this is how most people get about in 2023.

I dont disagree. However, as the OP states, some of the interesting and out of the way places on Scotland's west coast don't always show well on digital publications, Antares being the exception. Indeed the older CCC chartless and the modern CCC Pilotage guides can be superior to digital information. But I accept what you are saying is far more likely and common than these examples.

 

[Daydream believer]

Sailing around the Thames estuary,or allong a coastal trip ( ie France) I log when I pass various marks on shore or buoys etc.
Sailing out of sight of land to, say, Belgium, I log the distance I have travelled from a known point & course that I have sailed. That will enable me to work out on the chart where I might be. Normally I just set a course, look for indications on the way, & wait until I see land. Then look for landmarks to get a fix.
If using the plotter, then I will note distance to destination & bearing every hour. This will allow me to have a fixed point to start from, if the electronics fail.

 

[lustyd]

My only issue in Scotland's west coast was in Loch Fyne when skipper came clambering up the companionway shouting watch out for that rock on a cloudy night with almost zero light, and having no street or house lighting either. His paper chart used a different datum to the GPS and we were far from hitting the rock that we never saw or heard. I just continued looking at my handheld plotter at the helm and avoided the sides of the loch as best I could.

 

[Stemar]

For coastal sailing, I don't care about lat and long; what I need to know is that I'm far enough offshore to dodge the hard bits and going in the right direction. Knowing roughly where I am is helpful so I know how far to go to the next change of course, but that's all, until I need to find buoy X to go into Channel Y. Once I get far enough away from land that there's nothing apart from other boats to bump into and nothing to tell me where I am, I'm going to pay more attention, but my COG and off track error on the plotter are more relevant. All the same, I will log my position every hour in case the GPS goes down. At least then I'm in with a chance of finding the Cotentin Peninsular, even if I can't arrive directly at the uptide entrance to Cherbourg.

 

[Juan Twothree]

Had a real life experience of this dilemma a couple of years ago when I picked up a pot line just outside Poole harbour. Lovely sunny Saturday afternoon with light winds so no big drama. Coastguard required Lat and Long although I was ready to give a bearing from a major nearby navigation mark which is one of my waypoints. Took me by surprise as I know the RNLI will be using bearings and visual. I also learned that should a chopper be required they would be working to OS grid reference!

Since GPS came along I have always though that where you are in relation to a known fixed point (or more than one) is more important than an artificial point on map/chart.

The lifeboat can work with either. I find it quickest to tap the lat and long into the plotter, but it can also display a bearing and distance from a known object.

 

[AntarcticPilot]

As most of you know, I am a lifelong professional mapmaker and geographic information manager for Antarctica. As such, I dealt with latitude and longitude all day, every day, along with all the ramifications of map projections, datums, ellipsoids and many other arcane bits and pieces!

However, when in coastal waters, there's rarely any need to know your actual latitude and longitude; it's better to know where you are in relation to known points than where you are in a global coordinate system. Of course, I can find my latitude and longitude very easily - there are at least three systems aboard that display it, and one that will automatically transmit it to the CG in the event of an emergency. But I am rarely aware of my latitude and longitude; it's irrelevant to the sailing I do, and I would argue that it's only a routine necessity for those who are making passages out of sight of land.

Indeed, navigating according to latitude and longitude coordinates can lead you into danger, even in well-charted areas like the UK. Places like the East Coast have features such as bars at the mouth of rivers, and they change quite rapidly - just for example, the entrance to the river Deben has changed greatly this year. They certainly change faster than the update cycle of charts, especially electronic ones! But various bodies relocate the boys marking the safe passage, so when entering these rivers, you don't navigate with respect to fixed latitude and longitude, you navigate with respect to natural features and buoyage. Navigating with respect to latitude and longitude could easily see you wrecked in those waters - the chart from which you take the latitude and longitudes from is almost inevitably wrong!

In remoter parts of the world, it would be a very unwise assumption that charts are accurate to anything like the precision of GNSS, but they usually represent the relative position of features much more accurately than their absolute position. So in coastal waters in most of the world and even in well-charted places like the UK, it is better to navigate with respect to visible features and to know your position in relation to such features than to know your absolute latitude and longitude.

 

[lustyd]

update cycle of charts, especially electronic ones

An odd thing to say. I'd argue that electronic charts on board boats are considerably more up to date than paper charts on board boats. I've never personally witnessed an updated paper chart, despite several charters and RYA courses. My electronic charts are updated every time I switch on the plotter, and my Navionics included the new spit at Hurst within a matter of days.

 

[AntarcticPilot]

An odd thing to say. I'd argue that electronic charts on board boats are considerably more up to date than paper charts on board boats. I've never personally witnessed an updated paper chart, despite several charters and RYA courses. My electronic charts are updated every time I switch on the plotter, and my Navionics included the new spit at Hurst within a matter of days.

By update cycle, I mean the cycle of updating by chart suppliers. At best it's annual; usually longer. Of course new versions are released more frequently, but the updates incorporated will be on that sort of period at a particular location. Further, a new version will reflect the situation many months before the release date. As places like the Deben can change month by month - or even tide by tide in extreme cases - there's no way chart suppliers can keep up to date; there's only an annual survey on which to base updates, and that isn't usually incorporated in HO data anyway; a local "not for navigation ' chartlet is issued and Trinity House place buoys to mark the channel, but the chartlet is not available in a form that can be used in a plotter.

Ideally we would all check the compilation diagram or metadata if any chart data we use, but I'm probably one of the few who thinks to do that! Also, most leisure oriented chart data don't carry the metadata ..

 

[finestgreen]

Which is the part of the problem that "What Three Words" is intended to address. Pity it fails to address any other aspects!

The problem w3w is intended to address is keeping marketing and PR people in a job. Awful system and sad to hear the CG have been duped.

 

[Supertramp]

Perhaps the real question to ask is whether anyone has suffered a failure of electrics and lost the ability to navigate electronically while at sea?

 

[dunedin]

Perhaps the real question to ask is whether anyone has suffered a failure of electrics and lost the ability to navigate electronically while at sea?

Not sure that is a directly relevant question in that form.
For example, as well as the two main ships plotters, I carry a minimum of 3 other mobile devices with GPS and fully UKHO raster charts installed (for £25). I also carry a mobile battery booster - mainly for when travelling to/from boat, but I calculated when doing a trans-Atlantic, I could get a daily fix from my mobile phone using the battery booster, even if the phone was flat when disaster happened to the ships electronics. Plus enough left to run hourly for the final approach. (I also carry paper charts for my main cruising grounds)
I suspect most other (wise) skippers have a multiplicity of backup options. So “failure of electrics” is zero concern for navigation.

The real disaster scenario is if Putin or a major solar flare wipes out the GNSS (posh name for GPS and its equivalents) signal entirely. Then all the GPS devices are down. Or a lightning strike which wipes out all electronics on board (for which I try to mitigate by putting 2 mobile devices in the oven as a hoped for Faradays Cage, effectiveness fortunately not tested in practice).

 

[dunedin]

An odd thing to say. I'd argue that electronic charts on board boats are considerably more up to date than paper charts on board boats. I've never personally witnessed an updated paper chart, despite several charters and RYA courses. My electronic charts are updated every time I switch on the plotter, and my Navionics included the new spit at Hurst within a matter of days.

I agree that in the real world, electronic charts are generally much more likely to be updated than paper ones (in the absence of paid crew to do the chart updates).
But don’t be fooled by the “daily updates” from Navionics and the likes. They do best endeavours to update for major risks as quickly as possible - and looks like they did well with the Hurst Spit.
But I assume Navionics staff must have noted these reports and manually updated their database. The vast majority of chart data comes from the various national Hydrographic Offices - UKHO in the case of the UK. But I was amazed to learn that UKHO does not release updates to the leisure chart suppliers daily. It may be many months before they issue an electronic update to the likes of Navionics.
And as Antarctic Pilot indicates, even longer for paper charts and electronic raster charts.

 

[Supertramp]

Not sure that is a directly relevant question in that form.
For example, as well as the two main ships plotters, I carry a minimum of 3 other mobile devices with GPS and fully UKHO raster charts installed (for £25). I also carry a mobile battery booster - mainly for when travelling to/from boat, but I calculated when doing a trans-Atlantic, I could get a daily fix from my mobile phone using the battery booster, even if the phone was flat when disaster happened to the ships electronics. Plus enough left to run hourly for the final approach. (I also carry paper charts for my main cruising grounds)
I suspect most other (wise) skippers have a multiplicity of backup options. So “failure of electrics” is zero concern for navigation.

The real disaster scenario is if Putin or a major solar flare wipes out the GNSS (posh name for GPS and its equivalents) signal entirely. Then all the GPS devices are down. Or a lightning strike which wipes out all electronics on board (for which I try to mitigate by putting 2 mobile devices in the oven as a hoped for Faradays Cage, effectiveness fortunately not tested in practice).

Agree and what I meant - very few of us depend on one device. The ability to get at lat/long or use a GPS position is almost ingrained in a boat, and I suspect loss is rarely if ever a cause or contributor to disaster.

 

[AntarcticPilot]

I agree that in the real world, electronic charts are generally much more likely to be updated than paper ones (in the absence of paid crew to do the chart updates).
But don’t be fooled by the “daily updates” from Navionics and the likes. They do best endeavours to update for major risks as quickly as possible - and looks like they did well with the Hurst Spit.
But I assume Navionics staff must have noted these reports and manually updated their database. The vast majority of chart data comes from the various national Hydrographic Offices - UKHO in the case of the UK. But I was amazed to learn that UKHO does not release updates to the leisure chart suppliers daily. It may be many months before they issue an electronic update to the likes of Navionics.
And as Antarctic Pilot indicates, even longer for paper charts and electronic raster charts.

Another issue that gets discounted and actually worries me in the context of very rapid updates is that of QA. QA of map and chart data is non-trivial; I happen to know that the UKHO puts at least as much effort into QA as into compilation - I did some of it for Antarctic charts! And ideally, that includes at least one set of eyes other than the compilers'; people who have compiled something are conditioned to let their eyes pass things that a naive set of eyes will spot (we once let pass a rather embarrassing mis-spelling for exactly that reason!). The final step of our in-house QA was always to leave a proof copy of the map in a public area with plenty of foot traffic and let anyone who wished look at it and write comments on it - quite a few things were caught that way! My job was to do QA after the compilers had finished - that would usually take me at least several days doing fairly automated checks. Also, there isn't a vast pool of people working on these products. I don't know the details, but I'd guess it's tens of people, not hundreds. The well-respected Imray setup certainly isn't very large; one of my former colleagues worked for them, and many years later they still remembered her so it was obviously a small workforce (she was good at her job, but not otherwise memorable!). When I updated the master geographic database of Antarctica with data from an external source it would perhaps take me days to incorporate new data and then months to check it and correct errors introduced by adding the new data. That was, perhaps, more complex than chart data, but it indicates that QA is not to be regarded as easy or quick!

 

[Dellquay13]

I have a phone, stand-alone plotter and a HH gps on my little yacht so I have a few independent ways of getting a gps fix but on the rare occasion I feel the need to keep a detailed paper log when solo I find the quickest method with least time away from the helm is time speed and bearing from the cockpit dials and the lat/Long from the vhf display. One line on a sheet of paper and I have everything I need for a fix and DR if everything fails.
And if someone finds my boat looking like the Mary Celeste, they can estimate where to find my body, and not call me a careless idiot on the evening news

I do like Concertos idea of a photo, quicker but my phone battery life is rubbish

 

[AntarcticPilot]

The real disaster scenario is if Putin or a major solar flare wipes out the GNSS (posh name for GPS and its equivalents) signal entirely. Then all the GPS devices are down. Or a lightning strike which wipes out all electronics on board (for which I try to mitigate by putting 2 mobile devices in the oven as a hoped for Faradays Cage, effectiveness fortunately not tested in practice).

And this is a real concern; there is on record at least one solar flare that would have trashed the entire GNSS system (the Carrington flare), It happened in the 19th century, but it had major effects on telegraph systems; if such an insensitive system could be damaged, imagine what it would do to satellite systems with tiny signal to noise ratios!

More recently, unpredicted solar activity caused the premature demise of a batch of Starlink satellites. The orbits of GNSS satellites are immune to that particular problem, but it's always worth remembering that despite the almost casual use of satellites, "Space is hard"!

 

[finestgreen]

Another issue that gets discounted and actually worries me in the context of very rapid updates is that of QA. QA of map and chart data is non-trivial; I happen to know that the UKHO puts at least as much effort into QA as into compilation - I did some of it for Antarctic charts! And ideally, that includes at least one set of eyes other than the compilers'; people who have compiled something are conditioned to let their eyes pass things that a naive set of eyes will spot (we once let pass a rather embarrassing mis-spelling for exactly that reason!). The final step of our in-house QA was always to leave a proof copy of the map in a public area with plenty of foot traffic and let anyone who wished look at it and write comments on it - quite a few things were caught that way! My job was to do QA after the compilers had finished - that would usually take me at least several days doing fairly automated checks. Also, there isn't a vast pool of people working on these products. I don't know the details, but I'd guess it's tens of people, not hundreds. The well-respected Imray setup certainly isn't very large; one of my former colleagues worked for them, and many years later they still remembered her so it was obviously a small workforce (she was good at her job, but not otherwise memorable!). When I updated the master geographic database of Antarctica with data from an external source it would perhaps take me days to incorporate new data and then months to check it and correct errors introduced by adding the new data. That was, perhaps, more complex than chart data, but it indicates that QA is not to be regarded as easy or quick!

It always worries me when I click on something in the Navionics app and it says "updated by a Navionics User"!

 

[lustyd]

Perhaps the real question to ask is whether anyone has suffered a failure of electrics and lost the ability to navigate electronically while at sea?

No more than there were unprepared people caught out with paper.