
NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Silicon Sea: Leg 61
From: Dan Hogan
Date: 2000 Apr 03, 8:40 AM
From: Dan Hogan
Date: 2000 Apr 03, 8:40 AM
Chart(s): Planning Sheet Planning and Dead-Reckoning problem Leg 61 030400 Test your knowledge! ---------------------- ------ ------ -------------------- We arrived in Rio de Janerio on 4/05/2000. The boat has been refitted and supplied. The crew has plenty of rest and recreation in the wilds of Rio. It is time to start planning the remainder of the trip for home. >From Ocean Passages For The World: 9.60. Rio de Janerio to Europe or North America. 9.60.01. General Directions. Make first a stretch to the SE to about 35dW, and then stand N, in the South-East trade, crossing the equator between 27dW and 32dW; after passing through the doldrums, steer direct for American ports,... Jimmy Cornell's World Cruising routes recommends stopping in Guyana, Surinam, or French Guiana. After discussion we elect to head offshore and make Barbados our next stop. On Wednesday, May 3, 2000(03/05/2000) we depart Rio de Janerio. At 11:00:00ZT We take departure bearings giving us a departure position of (23d 30.2'S 043d 05.1'W). Our waypoints are: Mid Ocean Waypoint 1(MOP1): (29d 00.0'S 034d 00.0'W) Mid Ocean Waypoint 2(MOP2): (00d 00.0'N 030d 00.0'W) Barbados: (13d 10.0'N 59d 20.0'W) 1) What is the total distance to Barbados? -- --------------------------------------- 2) At a speed of 10Kts what is the total passage time in days to the nearest whole day? -- ----------------------------------------------------------------- Var 21dW Dev 2dE. Current Drift 0.6Kts Set 185d. 3) What is the TC(True Course) and distance to Mid Ocean Waypoint 1 (MOP1)(29d 00.0'S 034d 00.0'W) from our Departure point at (23d 30.2'S 43d 05.1'W)? -- ---------------------------------------------------------------- 4) What is the Compass Course(CC)/Course to Steer? -- ----------------------------------------------- After a day of getting our sea legs and final stowing for sea we manage a round of sights the morning following our departure. Body UT Hs Fomalhaut 08:13:11 56d 47.7' Deneb 08:15:10 18d 48.2' Antares 08:19:20 35d 56.1' Altair 08:20:00 53d 40.6' Vega 08:22:03 19d 36.5' 5) What is our FIX position? -- ------------------------- 6) What was the TC made Good? -- -------------------------- 7) What is the TC and Distance to MOP1 from our FIX? -- ------------------------------------------------- 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 - PSmith@IMPS0014.US.DG.COM John Simmonds- johnsimmo@bigpond.com Jim Manzari - manzari@bluewin.ch Dan Hogan - dhhogan@nav.cnchost.com Dan Hogan dhhogan@nav.cnchost.com