NavList:

Well, after ten days, I’ve finally experienced a Sun strong enough to experiment with. This rather puts the mockers on the idea of carrying a sextant for surface navigation in temperate latitudes in the event of GNSS failure, but that’s a different thread.  What we’re interested in is finding the bearing of a celestial body, in today’s case, the Sun without blinding myself.  First, I tried sticking my modern ski pole type walking stick into the ground as near vertically as I could.  Fore and aft movement towards the Sun made little difference to the shadow bearing, but lateral movement caused the shadow angle to change significantly, so the pole had to be vertical laterally.
Next I tried taking the bearing of the shadow.  The best and easiest way turned out to be to stand back and look down through a modern Silva style transparent walkers’ compass.  Line the lubber marks and the compass needle centre up with the shadow, and swivel the compass ring around to line up with the compass needle.  Read the bearing off the appropriate lubber line.  This was accurate to the width of the shadow, which was about two degrees.  I tried the same with my wrist watch for the Boy Scout method.  At 000 32’W, I needed to set my watch to UTC. The only problem was remembering to put it back to British Summer time afterwards.
After that I tried a few variations.  It being still airs, I dangled a plumb line from a clothes line, but by the time the very fine shadow reached the ground, there wasn’t much of it left.  Then I drilled a perfectly perpendicular 2.5mm hole through a block of wood and stuck in about 200mm of 2.5mm welding wire.  The shadow wasn’t quite strong enough to read on the compass.  A better idea would be to draw a line on the plank of wood about 400mm long with ink.  Swivel the wood until the shadow of the wire lines up with the ink line.  Line the lubber lines of the transparent walking compass up with the ink line, and swivel the compass ring round to line up with the compass needle.  Measure the bearing from the appropriate lubber line.  This has left me full of ideas for modifying the device into a proper pelorus for use on TIKI.  Dave