Re: [Paddlewise] surf landings and some other stuff

John Winters wrote:

> Dan , Ralph, and Robert commented on ferry angles;
>
> In my post I was speaking of the acute angle made by the course and the
> current direction. I suspect that Dan, Robert, and Ralph are talking about
> the acute angle between the course made good and the course normal (90
> degrees) to the current. If so, the 60 degrees corresponds to the 30
> degrees I was talking about (neat ehhh?)
>
> Not arguing over the comments but want to make sure I haven't confused
> anyone by using a different angle and talking about the increased
> resistance rather than the increased distance.
>
> I don't recall if Dan included the effect of the apparent current speed in
> his calculations. As he said it can get complicated. Hydrodynamic
> resistance can increase roughly by the  fourth power of velocity and that
> may complicate the calculations a bit. In other words, the decision as to
> whether to ferry or not may include more than just the extra distance
> travelled.
>
> Any thoughts or experience with this on this?
>
> Paddling upstream in reduced current may take less effort than paddling at
> an angle to the maximum current. Good old Marchaj (Sailing Theory and
> Practice) has a chart relating velocity to depth and river slope that is
> interesting
>
> While speaking of currents some might be interested in the currents I
> experienced in the McLelan Strait in Northern Labrador. The current is
> strong so we waited till there was an outgoing (west to east) tide. In the
> center of the channel the tide was running west to east but along the shore
> the tide was still running east to west. If you got caught in one of the
> whirlpools you could find yourself outside the shear zone and paddling your
> butt off while the other boat coasted past at high speed. The 20 - 30 foot
> tides in Ungava Bay caused lots of current problems and we would usually
> sprint across  and hop the eddies upstream.  Mind, the current was often
> much faster than  we could paddle in the center of the channels.
>
> Cheers,
> John Winters
> Redwing Designs
> Specialists in Human Powered Watercraft
> http://home.ican.net/~735769/
>

Gee...

I forgot my protractor I guess I'll have to go back to the put in and keep to
paddling on the local pond.

Robert Somerville
Toronto

PS Sewer surfers should try Mimico Creek in flood,  Toxicity and odors are
higher than the water

***************************************************************************
PaddleWise Paddling Mailing List
Submissions:     paddlewise_at_lists.intelenet.net
Subscriptions:   paddlewise-request_at_lists.intelenet.net
Website:         http://www.gasp-seakayak.net/paddlewise/
***************************************************************************