[mou] Buoy markers and state lines

[Jeff Dankert]

On the Mississippi River, boundaries between states usually run down the
middle of the main channel. (There are exceptions and a good map and
observed shoreline features are the only way to tell).

When birds and the state line are in the main channel, then finding the
main channel buoy markers is the task, as Benz explained in his Saturday
post about scoters.

The buoys are part of the U.S. Coast Guard's uniform waterway marking
system and they assist boaters. Unintentionally, they help birders as
well.

These buoys are not positioned in the middle of the main channel for
obvious reasons, and boaters in large craft know that to remain fully
navigable they must stay between the red and green buoys.

The red buoys are always on the left (port) side of the main channel
while heading downstream and the green buoys are always on the right
(starboard) side.

One way to remember this is that port wine is red. That also requires
knowing the port side is on the left, assuming downstream travel. When
heading upstream, the red is on the right.

That leads to another memory tool: "Red, right, returning." When you are
returning back upriver, the red buoys are always on the right.

If you are confused, then just remember this: Red buoys mark the
Wisconsin side of the main channel and a green buoy marks the Minnesota
side of it.

Neither buoy type marks the middle of the main channel, which is where
the state is. There are no buoys marking the middle of main channel on
the Upper Mississippi River.

Benz said the scoters were "on either side of a line connected by the
red buoys." That means they were definitely in Wisconsin, and may have
been flirting with the middle of the main channel and the Gopher state
when they were on his side of the red buoys.

Finding the approximate center of the main channel is a judgment but the
buoys help. If you bird the river, are concerned which state birds are
in, and especially if you are reporting unusual birds, this becomes
crucial.

Also look for "daymarks," larger fixed structures with lights that also
show the river mile, as well as the left or right side of the channel
(red or green lights and colors).

One more tidbit: Red buoys are called "nuns" and green buoys are called
"cans." They have different shapes, nuns with tapered tops and cans with
square tops. This helps navigate without color.

For this reason, red daymarks have triangular signs and green daymarks
have square signs.

The only other aid I can imagine birders using on the river, or other
large water body straddling a state line, is a rangefinder. An accurate
rangefinder would give the distance of birds from shore, and transferred
to a map, might help judge where they are were.

Regards,
Jeff Dankert
908 Parks Ave Apt 158
Winona MN 55987-5330
(507) 454-0033
renohawk@hbci.com