NavList:

Thanks David P. for your reply. I have been a "lurker" for some time and am aware of your knowledge of aviation navigation where you would have dealt with distant horizons. The pages from Norie will be helpful.

Thanks Frank R. for the info on refraction correction at altitude. 

I will certainly try to bring down a CB and see how it compares with AntiSpoof. Currently I have no view of the horizon due to thick smoke from Canadian fires. Since I have a limited amount to horizon to use, it has been difficult find a body during nautical twilight. Clouds, smoke, pollution have been conspiring against me, but I will persist. Venus has not been of much use to the west, but I must remember to do a meridian passage calculation.

Frank, thanks also for your suggestions for doing some CN on my cruise to Hawaii. So many days the skies were cloudy or the horizon not usable for various reason. I did take some sextant readings and I will see if I have enough info to work through them. Your tables were useful for what sightings I did reduce. Sadly, only one person on the cruise inquired about what I was doing.

At Kona (on the big island), we were anchored only 6-8 miles from where Captain Cook was killed. There is only a marker at the location. Apparently it is only reachable by small boat or a lengthy walk. I should have at least tried to find out more about getting there before I left. The book "Blue Latitudes" details with how the author visited the site. I will look at the book again. Cook must have had many days when he couldn't navigate either.