riverman wrote:

On a Grand Canyon trip many years ago (wow, like almost 20!!!) there was
such a headwind one day in Marble Canyon that I rowed with all my strength
for several hours and only gained about 200 yards of river. A big part of
the problem was that the wind kept blowing me into the shoreline eddys and I
would get washed back to the top of the stretch I had just rowed. After
about an hour, I was so exhausted that I let one of the clients try to row.
He got us blown back UPSTREAM from where we had started, and I had to regain
his ground as well as my own. We stopped and made lunch less than 2 miles
from where we spent the night before. It was the second hardest day ever on
a river....

What was the hardest day?

The Eel river between Alderpoint and Fort Seward is mostly wide open
with forest on the west bank and oak-dotted grassland on the east bank.
But at one spot the river narrows down with a cliff on each side, only
a dozen meters apart. The Eel is famous for prevailing northwest winds,
and we got to this spot in the afternoon, when upstream winds are at a
maximum. The three rafts on this trip took at least an hour, all rowing
as hard as possible, to make it past this spot.