<a href="https://en.wikipedia.org/wiki/Dredging" class="extiw" title="w:Dredging">Dredging</a> below <a rel="nofollow" class="external text" href="https://www.lrl.usace.army.mil/Missions/Civil-Works/Navigation/Locks-and-Dams/McAlpine-Locks-and-Dam/">McAlpine Locks</a>.
<p>Starboard side of <a href="https://en.wikipedia.org/wiki/Dredging#Cutter-suction" class="extiw" title="w:Dredging">cutterhead dredge</a> "Bill Holman".
The dredge is owned by <a rel="nofollow" class="external text" href="http://www.luhr.com/">Luhr Bros.</a>, contractor for the <a rel="nofollow" class="external text" href="https://www.usace.army.mil/">U.S. Army Corps of Engineers</a>, which is responsible for maintaining a navigable depth of 9 feet on the river .
(The Coast Guard maintains aids to navigation such as buoys, lights and daymarks).
</p><p>Note the <a href="https://en.wikipedia.org/wiki/day_shapes" class="extiw" title="w:day shapes">day shapes</a> atop the pilothouse.
The ball-diamond-ball sequence in the center indicates a vessel restricted in its ability to maneuver.
For a dredge, two balls in a vertical line indicate the side on which an obstruction exists.
(In this case, the discharge pipe runs from the dredge downstream to its terminus near the riverbank, so vessels cannot pass on that side).
Two diamonds in a vertical line indicate the side on which another vessel may pass.
(See <a class="external text" href="https://en.wikisource.org/wiki/International_Regulations_for_Preventing_Collisions_at_Sea#PART_C_-_LIGHTS_AND_SHAPES">COLREGs, Part C - Lights and Shapes, Rule 27</a>)
<a href="https://en.wikipedia.org/wiki/Kentucky_%26_Indiana_Terminal_Bridge" class="extiw" title="w:Kentucky &amp; Indiana Terminal Bridge">K&amp;I Bridge</a> in distance.
.
<a href="https://en.wikipedia.org/wiki/Ohio_River" class="extiw" title="w:Ohio River">Ohio River</a> mile 607.
<a href="https://en.wikipedia.org/wiki/Louisville,_Kentucky" class="extiw" title="w:Louisville, Kentucky">Louisville, Kentucky</a>.
July 24, 2002.
file # a2g080.
.
IMG_0303.
Canon PowerShot A40 digital camera.
</p>
JPEG quality 95.
<a rel="nofollow" class="external text" href="https://www.flickr.com/people/70020260@N04">William Alden</a> from Louisville, Kentucky, USA
CC BY-SA 2.0
<a rel="nofollow" class="external text" href="https://www.flickr.com/photos/bill_alden/42207034195/">a2g080: Starboard side of dredge Bill Holman</a>