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Dan,
Please check the compass bearings to the unknown bodies. They may be in
error.
Sam
----- Original Message -----
From: "Dan Hogan" <dhhogan@XXX.XXX>
To: <NAVIGATION-L@XXX.XXX>
Sent: Wednesday, May 23, 2001 5:42 PM
Subject: Silicon Sea: Leg 72 -NEW
> This is a TOTAL and complete revision to Leg 72. You can delete the
previous
> issue.
>
> My apologies.
> *************************
> Chart(s): Plotting Sheet
>
> Sight Reduction and                Revised
> Dead-Reckoning problem     Leg 72  052301   Test your knowledge!
> ----------------------     ------  ------   --------------------
>
> Our Last position FIX was (13d 00.0'N  61d 30.1'W) at 08:50:10UT on
> 30/05/2001. We are bound for a point on chart INT 401 marked as Aruba Gap
> (13d 50.0'N 70d 00.0'W). Aruba Gap provides a favorable westerly current
of
> 1.5 Knts.
>
> We have had overcast skys and have missed some possible sights. The winds
> have been fluky and we have had to tack several times since our last FIX
> position.
>
>     Tack 1: CC 333.0d - 04Hrs @XXX.XXX5 Kts - Var 12dW Dev 1dE
>     Tack 2: CC 242.0d - 11Hrs @XXX.XXX5dE
>     Tack 3: CC 262.0d - 08Hrs @XXX.XXX5dE
>     Tack 4: CC 307.0d - 10Hrs @XXX.XXX0dE
>
> 1)  What is the DR position at the end of the Tack 4?
> --  -------------------------------------------------
>
> 2)  What is the DR position local Zone Time(ZT) and Date?
>     What is the DR position GMT/UT time and Date?
> --  -----------------------------------------------------
>
> 3)  From the DR position, what is the TC to Aruba Gap
>     (13d 50.0'N  70d 00.0'W)?
> --  -------------------------------------------------
>
> Our speed is 8.5 Kts, Var 10dW Dev 1.0dE. Current Drift 0.7 Kts Set 265.0d
>
> 4)  What is the Compass Course(CC)/Course-to-Steer for Aruba Gap
>     from the DR position?
> --  ------------------------------------------------------------
>
> The following morning the navigator see stars through breaks in the
> clouds. He takes the following sights. Same data as for Q3 & Q4.
>
>     Body        ZT              Hs
>
>     UNKNOWN     05:39:00        13d 53.6' (Steering Compass Bearing
351.7d)
>     Mars        05:39:11        18d 14.5'
>     UNKNOWN     05:40:03        54d 58.9' (Steering Compass Bearing
329.3d)
>     Vega        05:41:06        40d 10.3'
>     Venus       05:43:33        35d 25.8'
>
> 5)  What is the FIX position?
> --  -------------------------
>
> 6)  What are the names of the two unknown bodies?
> --  ---------------------------------------------
>
> 7)  What is the TC and Distance to the Aruba Gap (13d 50.0'N  70d 00.0'W)
>     waypoint 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@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
>         John Simmonds-   johnsimmo@XXX.XXX
>         David Weilacher- daveweilacher@XXX.XXX
>         Tony Cappiello-  cappiello@XXX.XXX
>         Frank Norris-    NORRIS_FRANKLIN_H@XXX.XXX
>         Dan Hogan    -   dhhogan@XXX.XXX
>
>
> Dan Hogan
> dhhogan@XXX.XXX
>

   

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