|Lighthouses: Bay Features and Forces|
The Bay is an estuary, a place where fresh and ocean waters meet and mingle. It covers more than 2500 square miles and its main stem stretches some 180 miles with 12,000 miles of shoreline. Deceptively shallow, the Bay’s average depth is twenty-two feet; twenty-four percent of the Bay (some 700,000 acres) is 6 feet deep or less.
Fresh water flows into the Bay from 150 major rivers and 100,000 smaller streams and tributaries and drains a 64,000 square mile watershed that encompasses five states. Centuries of rivers and streams eroding the surrounding landmasses have given the Bay a soft bottom of sand and mud. Over time, the processes that created the Bay have also reshaped its shorelines and navigable channels—and still do. Other powerful natural forces in the Bay include fickle weather and changing seasons that bring ice, impenetrable fog, and brutal storms and hurricanes—some violent enough to erase familiar shorelines or remodel shoals in the course of a single wave-tossed night. In the lower Bay, treacherous currents and surging Atlantic Ocean tides menace vessels. There is no escaping the fact that the Bay’s changeable features and uncertain environment will always challenge even the boldest of mariners.
Place your mouse over the numbers on the diagram below to find out more about Bay features and forces.