NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
How much resolution is enough?
From: Greg B
Date: 2014 Dec 17, 12:24 -0500
From: Greg B
Date: 2014 Dec 17, 12:24 -0500
Hi All,
A couple of quick (?) questions raised by the the recent discussions
about the compact Haversine table and the Brown-Nassau Spherical
computer. I sail a Catalina 28 MK2 ( mid 1990's) so I am used to bobbing
about when underway. I must say up front that all of my celestial sights
are for fun - as I basically sail in Long Island Sound. Still it is a
skill worth
knowing to me. On land I can get a sight down to 0.1 or 0.2 NM I have
heard others say +/- 5NM would be good on the water - but on what size
vessel? Also if I take multiple sights, only at say, at the crest of a
wave -
- do I figure wave height into my eye height error? Seems like the math
really doesn't have to be any more accurate than the error inherent in the
sight.(?). I must also say up front that I love period navigation but my
little
Cat 28 + my skill level ='s no ocean going boat. So doing it on the sound is
going to have to do. But I have used my sextant for determining range
with good results (+/- 0.1 NM) while doing coastal i.e; DR +Pilotage, and
since I'm also a history buff (Huntington Militia) - I made a lead line
and log
line - good fun!
Many thanks in advance,
~ Greg
Svenska Flicka
Cat. 28 MK2
