NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Silicon Sea: Leg 78
From: Dan Hogan
Date: 2003 Jun 9, 09:19 -0700
From: Dan Hogan
Date: 2003 Jun 9, 09:19 -0700
Chart(s): Plotting Sheets
Sight Reduction and
Dead-Reckoning problem Leg 87 060903 Test your knowledge!
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We are bound for Mid-Ocean Point 1(MOP1)(40d 00.0'N 155d 00.0'W). Where
we plan on changing our course toward Mid-Ocean Point 2(MOP2)
(45d 00.0'N 124d 00.0'N).
Our DR position was (29d 22.4'N 160d 54.6'W) on 07/09/2002 @
20:20:30UT. TC 24.6d, Speed 10.5 Kts, Var 12dE, Dev 1dW, Current Set 035.0d,
Drift 0.3 Kts.
1) What is the Compass Course(CC)/Course-to-Steer to MOP1(40d 00.0'N
155d 00.0'W)?
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We continue on TC 24.6d, Speed 10.5 Kts, Var 12dE Dev 1dW. On the morning
after our last DR position of(29d 22.4'N 160d 54.6'W) on 07/09/2002 @
02:20:30UT. We manage a quick Sun sight through the broken cloud cover.
Sun LL Hs 27d 39.8'
2) What is the LHA and Declination of the SUN?
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3) What is the Azimuth(Zn) of the SUN?
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4) Using the steering compass, what is the compass bearing to the SUN?
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5) What is the TC and Distance to MOP1(40d 00.0'N 155d 00.0'W) from our
Sun LOP/DR position)?
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Speed 10.0 Kts, Current Set 273.0d Drift 0.4 Kts. Var 15dE Dev 1dW.
6) What is the Compass Course(CC)/Course-to-Steer to MOP1(40d 00.0'N
155d 00.0'W)?
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7) How many hours is it to our estimated arrival at MOP1?
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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
Dave Weilacher - daveweilacher@earthlink.net
Tony Capiello - anthony.cappiello@baesystems.com
Richard Berkowitz - richdberko@aol.com
Dan Hogan - dhhogan1@earthlink.net
