NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: How much resolution is enough?
From: Bill B
Date: 2014 Dec 17, 15:10 -0500
From: Bill B
Date: 2014 Dec 17, 15:10 -0500
On 12/17/2014 2:51 PM, Greg Licfi wrote: > 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? You do not need to add wave height to usual height of eye for dip. When you are at the top of the wave your horizon is the tops of other waves (hopefully not a predictable extreme nearby), so they cancel out--more or less. Reducing the argument to the absurd, if you were in the trough of a 30- foot wave your horizon would almost certainly be the top of the next wave. This is why we shoot from the tops. As an analogy, imagine yourself watching sunset from a mountain top using another mountain top of the same elevation as your horizon. Sunset should be on time. Now imagine watching the same sunset from a valley with the mountain between you and the sun. The observed "sunset" will be much earlier than predicted.
