Hi W,

You ask "In general how does one use these ideas to his advantage when
paddling? The general answer is that you can take whitewater paddling
classes or paddle with experienced whitewater kayakers. You need
whitewater skills to safely paddle strong flows that exhibit these
characteristics.

In whitewater, these water flows occur regularly and often intensely.
The whitewater paddler has to know how to handle them. These flows, and
others, are the reason whitewater paddling is so much fun.

In sea water, these water flows do occur, but usually not as regularly
or as intensely. However, it is wise for the sea paddler to have
whitewater skills also.

I learned more about paddling in one year of whitewater than in my
previous 10 years of sea kayaking.

Al Kubeluis

W. Watson wrote:
I've been browsing in some physics books, two in particular. "Physics
Simplified" by Epstein and "Mad About Physics" by Potter and Jardonski
(sp?). The idea of both books is to pose puzzlers and then explain their
answers. Both have more than a handful of questions that apply to
boating. One question involves undertow that is created by a sharp turn
in a river or stream. Another concerns flow from a narrow channel into a
wide channel and vice versa.

Suppose the turn is to the right. Then undertow is created near the left
bank. That is, water close to the bank moves downward, out to the
center, back up to the top, and then back to near the left bank, where
it descends again. In the case of channel width changes suppose the
channel widens, then according to the author, water will slow down as
one enters the wide channel. The effect is that when you enter a wide
channel your body will move slightly forward as though you are in a car
and put on the brake.

In another instance a problem concerns a main channel, and a rock on the
right, which produces back flow. In other words the water flows
clockwise around the rock and back upstream. Finally, another problem,
actually as part of the turn question above, mentions that 1. water
boiling up means water in that area is rising, and 2. water whirling
around means water is descending. Here is my question. In general how
does one use these ideas to his advantage when paddling? For example, is
there a paddling tactic that one should employ when noting that one is
about to enter slower moving water, and vice versa? As another example,
what tactic should be used when approaching boiling water? Maybe these
circumstances are handled by some general paddling strokes.

It just struck me that if these observations are right (the authors),
then there *might* be some way of handling them that is thought out and
one could use to there advantage instead of blindling paddling into the
action.

Both of these books contain more problems and their solutions that are
applicable to paddling.