NavList:

It is also fun to use a homemade nocturnal. (mine made from a £2  plastic school protractor.) Find the angle between trailing star of Cassiopeia and Big Dipper gives the Polaris correction directly.Just add or subtract to Ho. No tables, clock, almanac required. If you have these new fangled inventions, can even get a rough longitude in seconds. e.g get GHA Kochab. (that would be the angle measured by nocturnal at Greenwich) measure angle where you are. Difference of the  angle from GHA = longitude. (degrees east or west of Greenwich)

No sextant or visible horizon needed. However, my nocturnal only accurate to a degree, so not brilliant. However, most of my latitudes by this have been ok to 15'. Longitudes not so good.

I'm now thinking, what we need is a very accurate nocturnal that measures to say 1-5'? I may try making a big protractor but using sextant type scales + Vernia.

I suppose a camera could give an accurate angle? But that would be cheating! Astronomers I think have accurate graticule type eyepieces for their telescopes to measure angular distances?

All ideas welcome folks. In theory, only need watch and almanac + accurate nocturnal to get Lat and Long. (Unfortunately no good for the upside down folk down under!) I feel an interesting challenge coming on for winter nights approaching! Great how Navlist discussions stimulate lateral latitude (and longitude) thinking!

Francis