A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Frank Reed
Date: 2017 Oct 21, 11:21 -0700
Paul Hirose, you asked:
"How do you determine height of eye on one of these vessels?"
The easiest way is from a photo of the vessel. Yesterday in the FB celestial navigation group, someone posted some Sun observations with no indication on height of eye. He did post his coordinates which were on the east side of the Kattegat (between Sweden and Denmark), mentioned that they were at anchor there again, and said that he was taking sights from a bridge wing. So we pop onto the marinetraffic website, discover there's only one ship that fits the bill, and look up photos of it online. When you find a photo that is more-or-less beam on (a side view) and if you know the length overall of the vessel, you can easily determine the height of any point above the waterline. There's some ambiguity depending on loading of the vessel, but this gets you very close.