If the river is only 200 to 300 ft wide and you put out a safe amount of
scope you would have to anchor in the middle to allow for swing around your
anchor.

Don't count on the river current to keep you laying in the same direction
all the time. Winds can sometimes over come the currents set.

This location just doesn't sound like a "designated anchorage" and therefore
you would be at risk of being run into, even if you did have a anchor light
every night. You could also be liable for creating a hazard to navigation by
anchoring in an non designated place.

"a sail boat achored there for a week " does not a designated or safe
anchorage make. They may have been aboard at all times or near by on shore
to keep an eye on it.

If you are able to moor your boat at a safe secure marina for $1400 a year,
then you have a better deal than an open anchorage with no one to keep an
eye out for trouble. (that's about $1000 less than I pay per year.)


--
My opinion and experience. FWIW

Steve
s/v Good Intentions