NavList:
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Re: Silicon Sea: Leg 74
From: Michael Wescott
Date: 2001 Jun 16, 17:01 EDT
From: Michael Wescott
Date: 2001 Jun 16, 17:01 EDT
> Our last Running FIX(13d 37.8'N 68d 10.5'W) 16:30:29UT @XXX.XXX > We were headed for Aruba Gap(13d 50.0'N 70d 00.0'W). > On 02/06/2001 @XXX.XXX7 Nmi from our RFIX we made a course > change at the Aruba Gap (13d 50.0'N 70d 00.0'W) waypoint. Our destination is > Cristobal, Panama(09d 23.0'N 79d 55.0'W). We are anticipating a transit of the > Panama Canal. > Var 8.0dW, Dev 1.0dE . Current Set 275.0d Drift 1.5 Kts. Speed 10.4Kts. > 1) What is the the TC and Distance from Aruba Gap(13d 50.0'N 70d 00.0'W) > to Cristobal, Panama(09d 23.0'N 79d 55.0'W)? > -- --------------------------------------------------------------------- dLat = 9d23.0' - 13d50.0' = -4d27.0' = -267.0 dLo = -(79d55.0 - 70d00.0') = -9d55.0' = -595' dep = -595 * cos 12 = 582.0 TC = 270.0 - atan(267/582) = 245.4 > 2) What is the Compass Course(CC)/Course-to-Steer? > -- ----------------------------------------------- CC = 245.4 + 8.0 - 1.0 = 252.4 Correcting for current (on plotting sheet) gives course 242.5T or 249.5C > Since our turn at Aruba Gap(13d 50.0'N 70d 00.0'W)We have been sailing in a > steady wind and clear skys. > At 05:16:28ZT @XXX.XXX > Speed 10.4 Kts, TC 245.5d. > 3) What is the 05:16:28ZT DR position? > -- ----------------------------------- We're in the GMT-5 zone centered at 75d W 04-06-2001 10:16:28UT -02-06-2001 06:46:28UT ====================== 2 days 03:30:00 = 51.5 hr D = 51.5 * 10.4 = 535.6 dLat = 535.6 * cos 245.5 = -222.1 = -3d42.1' Lat = 13d 50.0'N - 3d 42.1' = 10d 07.9'N dep = 535.6 * sin 245.5 = -487.4 dLo = -487.4/cos 12 = 498.3' = -8d 18.3' Lon = 70d 00.0'W + 8d 18.3' = 78d 18.3'W DR: 10d 07.9'N 78d 18.3'W > We take the following sights: > Body UT/GMT Hs > Fomalhaut 10:17:22 47d 14.7' > Deneb 10:17:56 51d 52.0' > Altair 10:18:00 59d 18.2' Wow! only 4 seconds between sights. :-) > Vega 10:18:46 37d 34.3' > Venus 10:19:33 33d 20.0' > 4) What is the position FIX? > -- ------------------------- Using NAO sight reduction table and plotting sheet about 10d 29.0 N 78d 30.5W > Speed 10.0 Kts. Var 5dW, Dev 1.5dE. Current Set 100.0d Drift 0.7 Kts. > 5) What is the TC and Distance to Cristobal(09d 23.0'N 79d 55.0'W) > from the FIX position? > -- ---------------------------------------------------------------- Using plotting sheet TC = 232 D = 106 > 6) What is the ZT and Date of our ETA at the Cristobal waypoint > (09d 23.0'N 079d 55.0'W)? > -- ------------------------------------------------------------ Allowing for current, SOG is about 9.5 which is about 11:03 sailing time. That's 21:21 UT or 16:21 ZT same day 4-Jun-2001 <PRE> -- Mike Wescott Wescott_Mike@XXX.XXX </PRE>