A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: John Pinto
Date: 2021 May 21, 19:37 -0700
Yes a Polaris site at lower culmination (LHA=180) from an AP Lat of -1° does produce a very large negative F value (-179°). Not sure you really could see Polaris from that Latitude on a ship with LHA=180° but the Hc comes out to -1° so I guess it is just barely possible with a large enough HE.
Are there any other less extreme realistic cases that would generate say an F of -100° when taking a sight at sea where -1°<Hc<0° (I'm assuming that's a realistic limit for Hc when F is negative).