What would people recommend as a cheap but good, preferably non-electrical
tool for measuring horizon elevation at given bearings (magnetic
adjustments to be done afterwards)? I need to map out horizon lines for an
art project. Required accuracy is half a degree or better, both for
elevation and bearing.

I know I could use a decent compass for the bearing! :-) But I will be on
my own and will probably need to work pretty quickly, in some cases in
marshy conditions, so wondered whether there was an all in one tool which
would enable me to hold the bearing still while taking the elevation?

Thanks in advance.

Harry