A boat for an engineering-oriented tour of the <a href="https://en.wikipedia.org/wiki/Woodrow_Wilson_Bridge" class="extiw" title="en:Woodrow Wilson Bridge">Woodrow Wilson Bridge</a> project became stuck in shallow water in the <a href="//commons.wikimedia.org/wiki/Potomac_River" title="Potomac River">Potomac River</a>.  The silt flow is from the propellers attempting to force the boat through the blockage.
<a href="//commons.wikimedia.org/wiki/User:Thisisbossi" title="User:Thisisbossi">Andrew Bossi</a>
CC BY-SA 2.5
<span class="int-own-work" lang="en">Own work</span>