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
