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Subject: Silicon Sea: Leg 86
From: Dan Hogan (dhhogan1@XXX.XXX)
Date: Thu Nov 14 2002 - 09:23:47 EST
Chart(s): Plotting Sheets
Sight Reduction and
Dead-Reckoning problem Leg 86 111402 Test your knowledge!
---------------------- ------ ------ --------------------
We took a departure from Hanalei Bay, Kauai, Hawaii(22d 18.0'N 159W 30.0'W)
at 22:36:40UT 05/09/2002. We are bound for San Pedro, CA. Our course has
been planned to take us North, above the Pacific High and then turn East
until we can make for the Southern California coast.
Wind 035d Force 5, Current Set 195d Drift 0.3 Kts. TC 012.3d, Speed 10.3 Kts.
Var 11dE, Dev 0.5dW. Wave height is 12 feet from the NE period 18 secs.
Our planned Mid-Ocean waypoint 1(MOP1) is 1086.7 Nmi from Hanalei Bay
(22d 18.0'N 159W 30.0'W).
1) What is the DR position of our Mid-Ocean Waypoint 1(MOP1)?
-- ----------------------------------------------------------
We are taking a pounding and getting green water over the bow. So at
04:00:00UT we alter our 000.0d Compass Course(CC) 20d to port to ease the
motion.
2) What is the DR position at 04:00:00UT?
-- --------------------------------------
3) What is the new True Course?
-- ----------------------------
In broken cloud cover on the next morning we take the following sights,
Procyon is the first sight:
Body GMT/UT Hs
Procyon 15:34:00 33d 16.9'
Betelgeuse 15:35:03 57d 06.8'
Capella 15:36:01 63d 25.5'
Polaris 15:37:33 25d 17.8'
Jupiter 15:38:10 25d 24.2'
Sirius 15:40:22 32d 55.3'
4) What is the FIX position at 15:34:00UT?
-- ---------------------------------------
In a solid overcast we continue our True Course(TC) until 07/09/2002
@XXX.XXX
5) What is the DR position at this time?
-- --------------------------------------
6) How many miles have we traveled since our last FIX on 06/09/2002
(24d 30.1'N 160d 00.0'W)?
-- ----------------------------------------------------------------
The current and wind have veered to our port quarter. It appears that we
are north of the Pacific High. So we alter course for our original
Mid-Ocean Point 1(MOP1).
7) What is the TC and Distance to MOP1 from our current DR 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@XXX.XXX
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@XXX.XXX
Mike Wescott - wescott_mike@XXX.XXX
Dave Weilacher - daveweilacher@XXX.XXX
Tony Capiello - cappiello_ar@XXX.XXX
Richard Berkowitz - richdberko@XXX.XXX
Dan Hogan - dhhogan1@XXX.XXX
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