Gulf Stream 
The name “Gulf Stream" was first noted on Benjamin Franklin's 
chart of the Gulf Stream (about 1786). It appears to be derived from 
the region between Florida, Cuba, and the Bahama Islands, at one time 
called the Gulf of Florida, where the current begins. Some sources 
state that the Gulf Stream begins off Cape Hatteras, but such a view 
has been found impractical. 
The major part of the Gulf Stream is a well-defined swift current 
which begins north of Grand Bahama Island, where the Florida and 
Antilles Currents meet, and extends northeastward to about 40°N, 63°W. 
The approximate boundaries of this current, based upon thousands of 
surface ship drift observations, are shown in Figure 22. 
The Gulf Stream gains its impetus from the large volume of water 
that flows through the Straits of Florida, an amount that is estimated 
to be more than 20 times greater per hour than all the fresh water 
entering the oceans from all sources such as rivers, runoff, and 
thawing glaciers. 
The greatest calculated volume transport between 37°00' and 
38°20'N along 68°30'W is about 137 x 10° m>/sec; however, since this 
cross section extends only about half the width of the Gulf Stream, 
the actual total volume transport may be double that amount. 
Available data indicate that the Gulf Stream as shown in Figure 22 
is a permanent feature, particularly in the 8- to 10-mile-wide axis of 
maximum current speed. The flow prevails throughout the year, with 
only minor changes in direction; the speed varies slightly from one 
season to another, being higher during summer and lower during winter. 
