<snip>
Truely accurate Celestial Fixes require a perfect horizon, so anywhere other than the sea makes that difficult. 
<snip>  
Problem... No horizon visible on land...
Answer... Artificial horizon.
About $23.00 for a cheap plastic one that uses water for the reflector 
 
 to who knows how much for a mercury one like 
THIS ...
I only have one of the plastic ones...