From: Henry Halboth
Date: 2015 Jul 19, 14:43 -0400
One Navlist discussion on the accuracy of sextant sights at sea happened back in September 2010.
A pdf document of a study on this topic was attached to George Huxtable's post g14011. The average observational error, by experienced professionals on the relatively stable platform of a big ship's bridge was thought to be around 0.7' of arc.