NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Silicon Sea: Leg 74
From: Dan Hogan
Date: 2001 Jun 14, 7:05 AM
From: Dan Hogan
Date: 2001 Jun 14, 7:05 AM
Chart(s): Plotting Sheet Sight Reduction and Dead-Reckoning problem Leg 74 061401 Test your knowledge! ---------------------- ------ ------ -------------------- Our last Running FIX(13d 37.8'N 68d 10.5'W) 16:30:29UT @ 01/06/2001. We were headed for Aruba Gap(13d 50.0'N 70d 00.0'W). On 02/06/2001 @ 06:46:28UT and at 107.7 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)? -- --------------------------------------------------------------------- 2) What is the Compass Course(CC)/Course-to-Steer? -- ----------------------------------------------- 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 @ 04/06/2001 we take some sights. Speed 10.4 Kts, TC 245.5d. 3) What is the 05:16:28ZT DR position? -- ----------------------------------- 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' Vega 10:18:46 37d 34.3' Venus 10:19:33 33d 20.0' 4) What is the position FIX? -- ------------------------- 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? -- ---------------------------------------------------------------- 6) What is the ZT and Date of our ETA at the Cristobal waypoint (09d 23.0'N 079d 55.0'W)? -- ------------------------------------------------------------ NOTE: Lat & Lo = XXd XX.X', Date=DD/MM/YY, HE 9 Feet, Index correction -2.5', Time hh:mm:ss in UT,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. DR(Ded-Reckoning)=position by sailings, EP(Estimated Position)=DR+current affect. 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 - Smith_Peter@EMC.COM John Simmonds - johnsimmo@dingoblue.net.au David Weilacher - daveweilacher@earthlink.net Tony Cappiello - cappiello@kearfott.com Frank Norris - NORRIS_FRANKLIN_H@LILLY.COM Sam Chan - schan@socal.rr.com Dan Hogan - dhhogan@veriomail.com Dan Hogan WA6PBY C27 "Gacha" dhhogan@verimail.com Nav-L Page: http://www.wa6pby.com