NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Silicon Sea: Leg 90
From: Paul Hirose
Date: 2004 Apr 6, 16:30 -0700
From: Paul Hirose
Date: 2004 Apr 6, 16:30 -0700
TC to MOP4 = 112. Steer 3 degrees left to correct for current. Speed over ground = 10.8. 1. Compass course to MOP4 = 097, distance = 624 nm Estimated position is 37 12 N 129 17 W at the time of the sun sight. Applying the sight gives 37 12 N 129 20 W as the new EP. 2. Triple interpolating HO 229 gives sun azimuth 95.7 from the new EP. 3. Moon sight DR position = 36 45 N 127 03 W. I didn't do a conventional running fix. Instead, I corrected my EPs by dragging them to the nearest point on the LOP after each sight. HP and SD weren't supplied in the problem; I used 55.6' and 15.1'. 4. "Running fix" at moon sight time = 36 24 N 127 01 W. 5. The fix is not too strong due to the angle between the LOPs and the 11 hours elapsed between them. They are both pretty good speed lines, though, and we seem to be making a little over the predicted speed. 6. There's no indicatin we're significantly off the original course, so TC to destination is still 112. Subtract 2 to counter the current. CC = 088. Distance = 330. 7. Mt. Tranquillon should become visible at 57 miles out if the air is clear. I used an E-6B aviation slide rule for time / speed / distance and current correction angle calculations. Plotting was on pieces of typing paper. Sight reduction with HO 229. As far I'm concerned, this message doesn't require any reply. I'd rather evaluate the results myself when the answers are published.