NavList:

OK, I apologize for rambling question the other day.  Very tired, looked at too many things at once, rusty, and I confused myself. I was working on a review of flare sightings on the horizon. Grabbing stuff from everywhere.

If I could reduce my question to one.. We approximate visible distance vs height of each object:  Often 1.17 * Square Root He (height of the eye. or object etc)

I was told a refraction approximation is included in the factor,  which can vary. I first learned it decades ago from USCG study guides as 1.14,  Then was "corrected" by someone and relearned it as 1.17, and I understand and the NOAA Coast Pilot Uses 1.15.

Refraction varies continuously along a path with atmosphere conditions and temp, particularly a concern at very low angles.  OK. Is there any rough rule  to bias your favorite constant selection.

Let's say:

• Its summer day and the 3 H's (hazy, hot, humid).....  constant is x.xx 
  (type of days we sees ships floating in the air.) Ok can't correct for that...but...
• Oops its now summer night, cooler and more damp...constant is x.xx
• Oh its winter North Atlantic (cold with sea smoke fog).... x.xx
• Ok in the warm gulf stream chasing fishies... x.xx
• Or I'm near the coast looking at lighthouses so probobly more this way  x.xx
• Or I'm in open ocean far from shore so its more likely x.xx

Maybe more pontification and stupidity on my part.  A jelly bean, but... Just wondering which factor you would pick and why.

MC