NavList:

I went out with my latitude stick tonight and did some testing.  First impressions are that is shows more promise than I expected, but it’ll need a lot of refining and practise.  Firstly, as already stated you need a long stick.  Arms-length is probably too far for 45°-60° north.  You need help to define the vertical, possibly a plumb bob damped in a bucket of water or another crew member advising from a distance, which is possible on an east-west course.  You also need to be certain of what is arm’s length, possibly using a length of string between stick and mouth.  You would need to see the northern horizon at night.  It’s a while since I checked that.  Finally, you need to be able to see the top of your stick in the dark, possibly with a piece of glowing candle wick.  A red led would do today.  I did most of my test against Mars at just less than 60°, because the light pollution from Lincoln to my north makes Polaris very difficult to see.  In general, I appeared to need much more stick above the horizon than arm’s length x tan latitude suggested, and I’ve still to work out why.  If the mathematical solution doesn’t work at higher latitudes, then perhaps a better solution is to mark heights for known places before leaving Europe.  Then you would at least know you were in the same latitude as such and such a place.  This would be valuable for getting back home safely.  DaveP