NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Silicon Sea: Leg 88
From: Dan Hogan
Date: 2003 Jun 25, 06:29 -0700
From: Dan Hogan
Date: 2003 Jun 25, 06:29 -0700
ATTN: I am going sailing for a few weeks so the next Leg of Silicon Sea will not be posted until after mid-August. Cheers -Dan- **********************CUT HERE****************************************** NOTE: Since we are close to home port arrival for Silicon Sea, the remaining celestial problems will use the 2002 Nautical Almanac. Chart(s): Plotting Sheets Sight Reduction and Dead-Reckoning problem Leg 88 062503 Test your knowledge! ---------------------- ------ ------ -------------------- We are headed for Mid-Ocean Point 1 (MOP1) (40d 00.0'N 155d 00.0'W). On 09/09/2002 @ 03:30:20UT our DR position was(34d 10.4'N 150d 20.2'W. TC 327.4d, Speed 10 Kts, Drift 0.4 Kts, Set 273.0d. Var 15dE, Dev 1dW. 1) After 39Hours, what is the DR position? -- ---------------------------------------- 2) What is the Zone Time(ZT) and date of this DR position? -- ------------------------------------------------------- Since the sky is a solid overcast, we were not able to take any celestial sights. We decide to alter course for Mid Ocean Point 2 (MOP 2) (45d 00.0'N 118d 15.1'W). 3) What is the TC and Dist to MOP 2? -- --------------------------------- Var 11.0dE, Dev 1.5dW, Current Drift 0.4 Kts, Set 120d. Speed 10 Kts. 4) What is the Compass Course(CC)/Course-to-Steer to MOP 2 (45d 00.0'N 118d 15.1'W)? -- -------------------------------------------------------- On this same day at a DR position of (39d 46.1'N 153d 54.8'W) at 12:12:34ZT we manage a quick sight of the SUN. Var 11.0dE, Dev 1.5dW SUN LL Hs 54d 48.1' 5) What is the Estimated Latitude line of this Sight? -- --------------------------------------------------- At 05:10:21UT 11/09/2002 we manage a sight of an unknown body through a break in th cloud cover. Bearing by Hand Compass 266.4d, appearing to be a magnitude 0.1. Hs 33d 45.0' 6) What is the Name of this Body? -- ------------------------------- Using the earlier SUN sight and this Body sight for a running FIX. 7) What is the Running FIX(RFIX) position? -- ------------------------------------------------------------- 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 Mike Wescott - wescott_mike@emc.com Tony Capiello - cappiello_ar@netzero.net Richard Berkowitz - richdberko@aol.com Dan Hogan - dhhogan1@earthlink.net