Compass Declination Change. North Pole Magnetic Drift Update.

[GregOddity]

So, it seems we need to change the declination used on the compass. As I am certainly not a specialist on the issue I’ll wait to see if a fellow forumite could elaborate on the significance of the change in declination for us in the UK or when travelling North to higher latitudes.

https://www.ncei.noaa.gov/news/world-magnetic-model-out-cycle-release

 

[Randolph]

To avoid confusion it's called variation in British English.
Interesting though it is, as long as you follow the rules I don't see any practical significance. In most UK waters in recent years, we have got used to ignoring variation as our chart-plotting pencils are not sharp enough to plot the difference between True and Magnetic. It looks like it will become significant again - as it was when I started sailing.
Check the variation on the chart and apply it using your favoured mnemonic and keep the chart plotter updated. Whether variation is zero or 25 degrees the rules remain the same.

 

[AntarcticPilot]

Basically, in latitudes where a magnetic compass is useful, don't worry about it; just apply the deviation and variation printed on the chart. Magnetic compasses are unreliable in the polar regions, for several reasons (weak horizontal component of the field, solar influences on the field and extremely rapid changes in deviation both spatially and temporally), so other types of compass are preferred. Incidentally, GPS reception can be unreliable in the auroral zone, though less so than it was before the constellation was complete.

 

[GregOddity]

To avoid confusion it's called variation in British English.
Interesting though it is, as long as you follow the rules I don't see any practical significance. In most UK waters in recent years, we have got used to ignoring variation as our chart-plotting pencils are not sharp enough to plot the difference between True and Magnetic. It looks like it will become significant again - as it was when I started sailing.
Check the variation on the chart and apply it using your favoured mnemonic and keep the chart plotter updated. Whether variation is zero or 25 degrees the rules remain the same.

Basically, in latitudes where a magnetic compass is useful, don't worry about it; just apply the deviation and variation printed on the chart. Magnetic compasses are unreliable in the polar regions, for several reasons (weak horizontal component of the field, solar influences on the field and extremely rapid changes in deviation both spatially and temporally), so other types of compass are preferred. Incidentally, GPS reception can be unreliable in the auroral zone, though less so than it was before the constellation was complete.

Well we do intend and do our best to keep proficiency with Variation, to use the British term. We are intending to do high latitude sailing and that will be in areas that will be affected. My previous Artic experiences taught me not to rely on any single method of navigation, as I found myself more then once without GPS coordinates or a Jack Sparrow compass turning left and right all of a sudden. I found myself taking notes and plotting my routes. (overland not sailing). I do have to get an Octant because I have not touched one since my youth.
My doubt is the degree of Variation to apply to the one given on the chart. We do sail in the Solent at the moment but we also make a passage plan on paper and keep sightings etc etc to keep sharp. Becomes a bit of a past time and challenge sometimes. But I do like to feel confident on my skills before I jump into deep water.
I did not grasp the concept last night on how much do we need to apply to the value stated. Therein lays my doubt.

 

[Randolph]

I stressed the British use of “variation” to avoid confusion with “declination” in Astro navigation - I guess they can cope with the confusion in the US.
Apply all the variation given on the chart including the annual correction given. If you are sailing in the Solent, the present variation is 36 minutes West, according to http://www.magnetic-declination.com. I don’t have a chart handy. So in practice not worth bothering with.
However if you really want to annoy the helmsman you would add (because it is Westerly variation) that 36 minutes to your course to steer on the chart to get your compass course to steer.
Conversely, if you take a bearing with your hand-bearing compass you would need to subtract 36 minutes from the bearing in order to plot it as True on the chart.
My experience of high latitude navigation is limited to aircraft in the early Bronze Age. Luckily we had a navigator right behind us who used Grid Navigation (plenty about it on Google). While I understood it in theory, I have no practical experience. I just pointed the aircraft where the navigator said.
All sorts of mnemonics to remember which way to go, some for adults only. I use “variation West: magnetic best. Variation East:magnetic least”
I hope that’s what you were asking, otherwise I’m teaching your grandmother to suck eggs

 

[GregOddity]

I stressed the British use of “variation” to avoid confusion with “declination” in Astro navigation - I guess they can cope with the confusion in the US.
Apply all the variation given on the chart including the annual correction given. If you are sailing in the Solent, the present variation is 36 minutes West, according to http://www.magnetic-declination.com. I don’t have a chart handy. So in practice not worth bothering with.
However if you really want to annoy the helmsman you would add (because it is Westerly variation) that 36 minutes to your course to steer on the chart to get your compass course to steer.
Conversely, if you take a bearing with your hand-bearing compass you would need to subtract 36 minutes from the bearing in order to plot it as True on the chart.
My experience of high latitude navigation is limited to aircraft in the early Bronze Age. Luckily we had a navigator right behind us who used Grid Navigation (plenty about it on Google). While I understood it in theory, I have no practical experience. I just pointed the aircraft where the navigator said.
All sorts of mnemonics to remember which way to go, some for adults only. I use “variation West: magnetic best. Variation East:magnetic least”
I hope that’s what you were asking, otherwise I’m teaching your grandmother to suck eggs

yeah it is. I’m also from the early bronze age. My grandpa was the captain and Navigator and I also just pointed the boat anywhere he said. Flying I did in the modern age and we did not have to do any of that. Nor did I have a navigator. But I’ve never flown a crate in high lat neither. Only in beautiful skies where you almost have to dive to be able to get the thing down because of thermals. Or run like hell from some pretty big clouds that come out of nowhere.
Going to get my charts out and see if I don’t get it somewhere close to the south pole plotting a course to the Isle of Wight
I’ll let you know how it goes.