I was out today with a friend who is new to paddling and I saw her
have a problem I've only seen a few times before and can't explain.
She was paddling a poly Prijon Seayak and could not get it to track
straight to save her life. The rudder was up (control line was
broken) but since there was not much wind I figured it wouldn't matter
much. We were paddling with the tide the whole way and it was pretty
strong at times.
It got so bad that at times she was paddling entirely on the right
side of her boat and still turning to the right! I watched her
stroke thinking maybe she was dragging the paddle at the end and
creating a rudder effect like with a J stroke but I didn't see that
happening. Her stroke isn't perfect, but I didnt' see anything that
would create the situation she was experiencing with great
frustration. Finally we found a sandy bank and switched boats with
her in my old Perception Sea Lion and me in the Seayak and it didn't
help. She still couldn't get the boat to track straight. I found
the Seayak a bit more skittish on the water (the wind picked up at
times) but didn't have any problem paddling it straight.

Now I've seen this happen with at least one person before (in
different boats) and we never could figure out what was causing it.
We tried changing the paddler's balance, paddle grip, and other
variables without success.

I keep thinking it must have to do with the strong tidal current that
we were paddling with but I'm not sure I can figure out why it would
be and why I wouldn't have been similarly affected. At one point
when she was in the Sea Lion I had her turn the boat around and paddle
against the current and she said it was "better".

Can anyone shine the magic light of experience on this for me?

Thanks,
John