Re: [Paddlewise] speed with versus against the current

-----Original Message-----
From: John Winters <735769_at_ican.net>
To: paddlewise_at_lists.intelenet.net <paddlewise_at_lists.intelenet.net>
Date: Saturday, May 30, 1998 4:18 PM
Subject: Re: [Paddlewise] speed with versus against the current


>David wrote;
>
>(SNIP)
>>
>>The V, of course, is velocity of the paddle relative to the water.  So,
>>if you are paddling with
>>the same cadence and stroke length, etc. (neglecting for the moment the
>>effect of
>>wind speed on your velocity relative to the water), you produce the same
>>thrust whether you
>>are paddling upstream or down.
>
>Keep in mind that you are paddling at the same cadence relative to the boat
>and yourself. The paddle velocity relative to the water is the key point.
>The thrust developed is a function not of the paddle velocity relative to
>the boat but the velocity relative to the water.
>
>>You also move at the same velocity
>>relative to the water.
>
>Maybe maybe not. Even if the force developed is the same you may not move
>at the same speed due to the way the transverse wave system forms around
>the boat. I don't klnow if nayone has studied this but my observation is
>that the wave system created by the boat is much modified by the flowing
>water. Perhaps Bruce has some thoughts on this. Are you there Bruce?
>
>>Your speed made good (speed over ground) is then the vector sum of your
>>velocity
>>relative to the water and the velocity of the water relative to the
>>ground.
>
>Also not necessarily so since it assumes that the two are perfectly
>additive but they aren't because of the time between strokes when the boat
>will slow at different rates.
>>


In my note in this thread I was referring only to paddling with or against
current.  No wind; No waves.  I think, (not sure), that with my eyes closed
I could tell whether it was with or against.

John Winters says that the velocities of water, and of boat with respect to
water, are "not necessarily additive".  This accords with my sense.  But I
still can't think why, assuming that you are in a steady state and not
crossing eddylines.

As far as wind is concerned (another topic entirely), I can't imagine why a
wind at your back is not easier from an effort, not handling, point of view
than a wind in your face.

Jerry

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