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(Joe) wrote in message . com...
otnmbrd wrote in message

Not always true on the river. I'm going to assume by middle of the
channel you may be meaning the physical middle between the banks.

Interesting info about the mississippi and the ship wreck area from
James Varney of the times picayune:

The route from New Orleans to the open sea is one that has bedeviled
the maritime industry for more than 125 years.

The aquatic artery moves in a powerful swift line for roughly 100
miles from the Crescent City Connection to Head of Passes, where the
Mississippi glides over a sand bank and becomes a three-pronged fork.
The main pass -- the one in which the Lee III was scuttled in a thick,
5:30 a.m. fog -- is known as Southwest Pass. It offers a relatively
straight, 14-mile shot to the Gulf of Mexico. Another, less traveled
route is called South Pass, and the third, which isn't navigable to
the Gulf, is named Pass a l'Outre.

Given the options -- which also include the manmade Mississippi
River-Gulf Outlet, or "Mr. Go" -- it would seem traffic headed upriver
could continue to flow even if the Southwest Pass were blocked. For a
variety of reasons, some artificial and some attributable to the
river's own mighty will, that is not the case.

Nor has it been the case since James Buchanan Eads began agitating in
1874 for federal money to dredge one of the delta's fingers and make
it available for commerce. His first choice was the Southwest Pass,
which he correctly saw as the only one wide enough to handle
increasing traffic. For several reasons, however, Eads was stymied. He
was given the South Pass while his arch foe, Andrew Alexander
Humphreys, began work on the Southwest Pass.

Although Eads eventually beat Humphreys, and got the South Pass to a
depth of 28 feet, his foresight proved correct.

"In fact, the (depth of the) water flowing over the bank there into
the South Pass is the exact same today -- around 9 feet -- that it was
in 1875," said John M. Barry, the Louisiana historian and author of
"Rising Tide," a chronicle of the Mississippi's epic 1927 flood.

Today, the Corps' steady dredging keeps the channel draft in the South
Pass at 17 feet, a depth that might have accommodated the Lee III but
is nowhere near deep enough for a colossus like the ZIM Mexico III.
The Southwest Pass, by contrast, has a channel ranging between 45 and
65 feet deep, Mujica said.

Even that can fluctuate. When it's foggy, and the Corps can't get its
survey boats on the water, river sediment can build up so fast the
bottom will rise 3 feet in 24 hours.

"Keeping a deep-water pass in the Mississippi River is no children's
game," Corps spokesman John Hall said. "There's a premium on
horsepower out there, and as the deep water swings from side to side
in the bends, it's like switching back and forth from American highway
traffic to a British highway system."

Thus, the Corps updates its charts on a 24-hour basis and transmits
them to Pilottown, where they are posted on a war room wall. The most
up-to-date depths, in other words, are available.

But in the case of the crash between the Lee III and the ZIM Mexico
III, the depth was less important than width. Given that the channel's
surface width is only 750 feet, that after the collision the Lee III's
stern was poking above the surface, and that the area was quickly
swarming with Coast Guard and salvage boats, there simply was no room
for a ship, regardless of draft, to get through.

I thought it was the bow sticking out of the water.

Joe