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Older Silicon Sea results
From: Ed Falk
Date: 1999 Jul 06, 13:49 EDT
From: Ed Falk
Date: 1999 Jul 06, 13:49 EDT
Hi all; I've been going through the older Silicon Sea legs and am having problems getting some of them to reconcile. For instance, leg 49 gives the following problem: Our last position FIX was at (35d 00.2'S 156d 59.7'E) at 09:05:22 @XXX.XXX Current Drift 17 mi/day, set 185 according to the Pilot Chart. We continue on course through the night. The weather is deteriorating and it begins to rain. At 19:45:00GMT the wind heads us and we are forced to change our Compass Course(CC) 45d to port to stay close-hauled. As I read it, the last sentence means we turn 45 degrees to port, to a new true heading of 86.8 - 45 = 41.8. However, Answers.txt says the new True Course Made Good is 72 degrees. The current can't be *that* strong. Have I made a mistake somewhere? Even assuming that the puzzle meant to say that we turn port to a compass course of 45 degrees mag., that gives me a TC of 60 degrees, and after factoring in the current, CMG = 64 degrees @XXX.XXX The second part of the puzzle gives this table: TC Speed Dist Time/in/Hrs 072d 8.7 91.3 10:30:00 027d 8.7 52.2 18:30:00 122d 7.5 198.1 26:25:00 095d 9.5 311.1 32:40:00 I don't quite know how to read this. Are the distances & times cumulative? I don't see how that can be, since the second distance is a smaller number than the first. However, I find it hard to believe that it took 18:30 to travel 52 miles @XXX.XXX I had problems with the first part of the puzzle too, where it asks for the DR position at the time of course change. I did it with plotter and paper and via computer and got roughly the same answer (35?S, 158?'E), but Answers.txt gave 34?.7'S for the lattitude. How do I determine Zone Time from lat,lon? Is there a chart I'm missing? I'm convinced there are at least some errors in Answers.txt. For instance, in Leg 46, the answer to question 1 about total distance is 114,112.8 mi which I'm pretty sure is wrong. Even *I* don't get that lost. Thanx in advance for any advice you can give. -ed falk