Two On A Big Ocean The Story of the First Circumnavigation
of the Pacific Basin
in a Small Sailing Ship


      

Other Books by
Hal Roth
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Re: Silicon Sea: Leg 83 Answers


Subject: Re: Silicon Sea: Leg 83 Answers
From: Dan Hogan (dhhogan1@XXX.XXX)
Date: Thu Sep 26 2002 - 21:17:22 EDT


On 27 Sep 2002, at 9:05, Peter Fogg wrote:
{Snip Navig data]

> For the first segment we are given, apart from the speed of 10 k, a
> Current Set 095d, Drift 0.7 Kts. Yet the time above for the 140 nm run,
> 14:00:00 Hrs, indicates the speed used was the 10 k rather than a lesser
> speed
> influenced by the contrary current, a SMG of about 9.3 k.It makes for
> about an hour's difference. I don't understand this apparent inconsistancy.

The problems are based on the DR. But, I have been known to mess up the
questions.

Speed Made Good(SMG)is an after the fact result of the navig calculations.
And are not used in the calculations.
>
> The rest is minor - Distance 10.4 / SpMdGd 9.4 = 1h 06m 23m, rather than
> 01:06:54 Hrs, just as Distance 25.4 / SpMdGd 10.3 = 2h 27m 58s, rather than
> 02:27:42 Hrs. Can imagine these small differences come about from the
> calculator using internal data that is more precise than that displayed, which
> is rounded to specification.

Ther will be slight differences, excluding my goofs, depending on the
techniques used for solving the problem.
>
> Despite these whinges and moans, enjoy these Silicon Sea exercises greatly.
> Long may they sail.

Cheers
-Dan-





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