NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Theoretical Question - Height of Eye from Shore
From: Gary LaPook
Date: 2007 Nov 18, 00:13 -0800
From: Gary LaPook
Date: 2007 Nov 18, 00:13 -0800
Gary LaPook writes: I also use the beach at Ventura for taking sights, I like the one right behind the fairgrounds. gl Greg R. wrote: >OK, here's a question for the theorists on this list... If I'm doing >sextant shots from shore (vs. on the water itself), do I need to factor >in the height of the tide into my He corrections? > >I actually surveyed one of my favorite locations with a handheld >transit/bubble level device and a surveyor's rod (to get an elevation >measurement accurate to within a couple of inches or so), but it dawned >on me that measurement would only be valid for the state of the tide at >the time. > >This particular location (Ventura, CA) doesn't have a huge tidal range >- maybe 3-4 feet - but it got me to thinking that other locations with >a much greater tidal range would probably be affected enough to where a >correction would be necessary to get the same accuracy that you'd >expect from being on the water. > >-- >GregR > > >> > > > --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to NavList@fer3.com To , send email to NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---