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Sight Reduction and
Dead-Reckoning problem     Leg 76  050701   Test your knowledge!
----------------------     ------  ------   --------------------

We arrived on the Caribbean side of the Panama Canal on 04/06/2001. It is now
17/06/2001 and we have finally arrived at the Pacific side at Balboa. Since
it is a Sunday and we choose not to pay overtime, we motor the Balboa Yacht
Club. The initiation fee is $25.00 and mooring fee is $00.50 per each
complete foot per night. We spend two nights while we get our customs and
port clearances.

We then motor to the Isla Flamenco and anchor at(08d 55.2'N 79d 31.6'W) to do
the final trip planning, servicing, and provisioning the boat. We will motor
from our anchorage to abeam the Light at Isla San Jose(08d 10.5'N 079d
15.0'W). Speed 8.3 Kts. Our departure is planned for sunrise on 24/06/2001.

1)  What is the Zone Time(ZT) of sunrise at our anchorage?
    What is the UT/GMT time of Sunrise?
--  ------------------------------------------------------

2) What is the TC and Distance  from Our anchorage(08d 55.2'N 079d 31.6'W)
   to abeam of Isla San Jose Light(08d 10.5'N 079d 15.0'W)?
-- -----------------------------------------------------------------------

It is late in the season and the North Pacific storms are beginning so we
elect to bypass the Galapagos Islands. We will follow the recommendations in
Ocean Passages For The World and in World Cruising Routes and on departing
Isla San Jose Light(08d 10.5'N  79d 15.0'W) we will head for a Mid-Ocean
Point(MOP) at (03d 00.0'N  110d 00.0'W).


3) What is the TC and Distance to the MOP at (03d 00.0'N  110d 00.0'W)
   from Isla San Jose Light(08d 10.5'N  79d 15.0'W)?
-- ------------------------------------------------------------------

>From the MOP(03d 00.0'N 110d 00.0'W) we head to make landfall on the
Southwest coast of Hawaii(19d 30.0'N 154d 45.0'W). We have two alteratives
depending on current and weather, either a Great Circle Course or the Rhumb-
Line course.

4)  Calculate the Rhumb Line TC and Distance to landfall.
    Calculate the Great Circle initial course and Distance to landfall.
--  -------------------------------------------------------------------

5) To the nearest tenth of a day, what are the total days enroute from our
   anchorage at Isla Flamenco to the Southwest coast of Hawaii as our plan is
   layed out? Sailing Speed 9.5 Kts, motoring Speed is 8.3 Kts:

    Isla Flamenco (08d 55.2'N 79d 31.6'W)
    Isla San Jose Light(08d 10.5'N 079d 15.0'W)
    Mid-Ocean Point(MOP) at (03d 00.0'N  110d 00.0'W)
    Southwest coast of Hawaii(19d 30.0'N 154d 45.0'W)
-- ------------------------------------------------------------------------

Having a 6 person crew and water consumption at 1.5 US Gal/day per person.

6)  What is the expected water consumption for the trip to Hawaii?
--  --------------------------------------------------------------

7) Estimating 3lbs of food per day per person what is the total weight
   in food for the trip?
-- -------------------------------------------------------------------

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

   

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