NavList:
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Silicon Sea II: Leg 48
From: Dan Hogan
Date: 1999 Mar 03, 7:32 AM
From: Dan Hogan
Date: 1999 Mar 03, 7:32 AM
Chart(s): Sight Reduction & Dead-Reckoning problem Leg 48 030399 Test your knowledge! ---------------------- ------ ------ -------------------- Our last position FIX was at 19:32:20ZT @ 17/02/1999(34d 00.0'S 153d 30.2'E). Speed 8.7Kts, Compass Course/Course to Steer 89.1d. Var 12dE, Dev 2.5dE. Current Drift 17 mi/day, set 185. The distance log on the knotmeter indicates we have traveled 95.4 mi since our Last position FIX. The sky is brightening but we have a solid cloud cover. 1) What is the DR position at the 95.4 mi log reading? What is the GMT time and date? -- --------------------------------------------------- The wind begins to veer and we harden the sheets. Speed is 8.7Kts. 3Hrs and 20 min after our DR plot the wind heads us and we alter the Compass Course(CC) to 97.8d. The Pilot Chart shows we are in a 13dE Var area. Dev is 2.0dE. 2) What is the DR position at our course change? -- --------------------------------------------- 3) What is the new TC? -- ------------------- 4) What is the Compass Course Made Good? -- ------------------------------------- We continue on this course for the remainder of the day. At 09:00:00GMT we take sights on the following bodies. As usual use the time of your first sight for plotting. GMT Body Hs 09:00:00 Saturn 24d 13.1' 09:05:22 Betelguese 47d 06.2' 09:07:00 Rigil Kentaurus 11d 52.1' 09:09:10 Miaplacidus 44d 13.8' 09:15:19 Procyon 40d 22.3' 5) What is the DR position at the time of the first sight? -- ------------------------------------------------------- 6) What is the FIX position? -- ------------------------- 7) At the time of our initial sight there was a bright body low on the horizon at about 261d by the compass. What body was this? -- --------------------------------------------------------------- NOTE: Lat & Lo = XXd XX.X', Date=DD/MM/YY, HE 9 Feet, Index correction -2.5', Time hh:mm:ss in UTC/GMT,unless otherwise stated. Silicon Sea II is a 34,000 lb(15.40t) displacement sailing vessel, 48' 3"(14.70m) LOA. 39' (12.00m) LWL; Cutter rigged. Can tack to 45d. Water Tanks = 220 gal(1000 ltrs). Fuel Tanks = 155 gal(700 ltrs). Fuel consumption .675 gal/Hr at 8.5 Kts. Dist to Horizon: Nmi = SQRT HE@mtrs x 2.07; Nmi = SQRT HE@ft x 1.17. PLEASE respond with your results and thinking on these exercises to the NAVIGATION list at large. If you have questions or problems, A lot of folks on the list are knowledgeable and willing to help. Any questions or doubtful areas will be responded to promptly. Let us hear from you soon! Good Navigating! -=The Navigation List Working Group=- Peter Smith - psmith@wellspring.us.dg.com John Simmonds- mobi@netconnect.com.au Jim Manzari - manzari@bluewin.ch Dan Hogan - dhhogan@concentric.net Dan Hogan WA6PBY dhhogan@concentric.net Catalina 27 "GACHA" =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=--=-= =-= TO UNSUBSCRIBE, send this message to majordomo@roninhouse.com: =-= =-= navigation =-= =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=--=-=