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post #11 of 67 Old 02-16-2011
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More info neded. Is this a to windward or to leeward finish?
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post #12 of 67 Old 02-16-2011
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Assuming that both boats are heading in the same general direction toward the same finish line, and that the statement "Boat B has no wind" does not mean apparent; Boat B would have 10 Knots apparent ON THE NOSE. This will slow boat B..

Boat A would have 0 Knots apparent.

Boat A wins
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post #13 of 67 Old 02-16-2011 Thread Starter
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Quote:
Originally Posted by RichH View Post
More info neded. Is this a to windward or to leeward finish?
See OP....10 knots from astern but to be completely clear both boats are directly downwind from the finishing line. Current is also running in same direction as wind.

I'll post answer later in the day. It is as much the why as the winner.

I had a lot of fun with this. Hell, me and the Wombet nearly came to blows .

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post #14 of 67 Old 02-16-2011
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Quote:
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Both are in a ten knot current flowing in the same direction as the boats.

Boat A has ten knot true wind from astern, Boat B no wind.
What will be the result ? A wins

Why ? because A is drifting toward the line at ~10kts but has 0 kts *apparent* across the sails and total forward speed to the mark is 10kts.;
B is drifting at 10 knots but with -10 knots (current v 'minus' TRUE wind ( approx. NEGATIVE 10 apparent ) across the sails ...

Rx: Both in same v of current; A has 0kts apparent; but B has NEGATIVE approx. 10kts. 'apparent' wind

Last edited by RichH; 02-16-2011 at 07:19 PM.
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post #15 of 67 Old 02-16-2011
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Aren't the boats upwind from the finish line if the wind is astern?

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post #16 of 67 Old 02-16-2011 Thread Starter
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Aren't the boats upwind from the finish line if the wind is astern?
The finishing line is downwind from the boat with the following true wind. The second boat has no true wind so the point is moot.

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post #17 of 67 Old 02-16-2011
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Boat A has 0 apparent wind because he is moving at 10kts with the current and the wind is also 10kts in the same direction. Boat B has 10kts apparent wind on the nose, so if they are allowed to change course (i.e. tack), boat B can sail upwind and get there first.

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post #18 of 67 Old 02-16-2011
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Yes. One assumes neither is motoring, and both theoreticaly can sail, but only one has relative wind. To say that B will be slower because the wind will push it backwards either assumes it can't sail or that no yacht can sail in 10 knots to windward.
Of course in the real world of sailing A would lose the wind and B would gain it so the positions would be reversed.
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post #19 of 67 Old 02-16-2011
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"See OP....10 knots from astern but to be completely clear both boats are directly downwind from the finishing line. Current is also running in same direction as wind."

If you have 10 knots coming over your stern and the current is flowing in the same direction, and the finish line is directly upwind, you are going straight away from the line in a big hurry. Neither boat will ever finish.

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post #20 of 67 Old 02-16-2011
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"Boat A has ten knot true wind from astern, ...
...both boats are directly downwind from the finishing line."

Sorry, fuzzy, but if that's all true BoatA must be sailing backwards, right?
Which is of course possible and legal within the rules. Probably means BoatB is going to win since BoatA is being blown away from the line and BoatB isn't.
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