NavList:
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Re: more Leg 57 results
From: Dan Hogan
Date: 1999 Aug 19, 13:26 EDT
From: Dan Hogan
Date: 1999 Aug 19, 13:26 EDT
>Here are the rest of my results for Silicon Sea Leg 57. > >4. ETA Cape Horn = Mar 26 0230 Z, Mar 25 2230 ZT. > >I divided the 297 miles measured on plotting sheet by 11.1 kt speed >(10.3 kt plus .8 kt current practically on our stern). Since the >current was stated, I assumed we were supposed to use it. Your procedure is OK. But doing distance measurement on a plotting sheet for more than a 2 degree area introduces large errors due to the scale. AND as I remember the error gets much worse on a small boat under sail in moderate weather. >5. Distance from 2342 Z fix to Cape Horn = 297 nm. See 4. above. >6. Compass course = 100. Within tolerance. But you can get more accuracy using one of the Sailings methods for DR. >7. TC & dist to decision waypoint = 76 deg, 146 nm. Same as 6. above. >Constructed a new plotting sheet for this question. > >8. Compass course = 66. OK >The problem says drift is "0.8 Kts/day". I assumed this meant 0.8 >kts. My E-6B says we should angle 2 deg right to correct for that >much current. Subtract the total compass error of 12 E to obtain >answer. AArrgghh! Yes the current *IS* 0.8Kts. Forget the per day thing. The new Pilot Charts list current in Kts as read on a knotmeter. Dan Hogan WA6PBY C27 "Gacha" dhhogan@XXX.XXX Navigation-L: http://nav.cnchost.com