NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Silicon Sea: Leg 88
From: Joe Schultz
Date: 2003 Jun 30, 23:48 -0500
From: Joe Schultz
Date: 2003 Jun 30, 23:48 -0500
Well, a dozen years and the rust has removed all of the paint. Here are my answers to the first part, followed by questions for the experts. I used a calculator with trig functions for the calculations and home-made sheets for the graphical solution (after locating my Speedbow, C-Thru ruler, and a metric scale). 1) L2 = 39d 39.0'N Lo2 = 154d 43.0'W via Mid Latitude Sailings L2 = 39d 39.0'N Lo2 = 154d 42.1'W via Mercator Sailings L2 = 39d 38.5'N Lo2 = 154d 43.9'W via three plotting sheets 2) 0830:20 ZT 10SEP2002 (1830:20 UT 10SEP2002 +10). Intermediate DRs were plotted every four hours starting 0400 UT 09SEP2002, since we are in the open sea. Questions: 1. Are there rules-of-thumb in terms of distance limits for which I decide to use Plane, Mid Latitude, or Mercator Sailings? 2. Plotting sheet dL = 0.5 Nm to calculated L2, which shows my current ineptitude in plotting (used 10 sheets of paper to get three "good" plots). How close to calculated Lo2 can I reasonably expect to arrive with a correct plot? Note that I cheated and used dL = 2d 20' for the middle plotting sheet.