NavList:

Dave,

There is a loss of contrast between the reflected horizon and the direct horizon when lining up the horizons on the whole horizon mirror. On horizontal angles the overlapping features get blended making identification hard. The split mirror can be cocked up a hair to have the nav aids one above the other to positively identify then overlapped for precision. Since I have both types of horizon mirrors on different sextants it is easier to compare the subtle differences on the spot.

Greg Rudzinski

From: David Fleming
Date: 2015 Nov 20, 10:01 -0800

Greg,

Could you explain:

The down side is that checking index error by horizon alignment is made difficult as are horizontal sextant angles. 

Thanks,

Dave