The Gulf Stream is an intense ocean current in the western North
Atlantic Ocean that is part of the circulation of water in this ocean
basin. It flows generally northward along the east coast of the United
States from Florida to North Carolina and then veers out into the
North Atlantic near Cape Hatteras, NC. The Gulf Stream forms a
boundary between the warm waters of the Sargasso Sea and the
colder, denser waters of the continental shelf. The Gulf Stream
current develops meanders, loops, and bends as it veers away from
the coast, so its exact position is variable.
See link at http://polar.ncep.noaa.gov/gsf/

                    http://rads.tudelft.nl/gulfstream/  (gulf stream velocity)

Satellite images of the east coast of the US provide visual information
about the postition of the Gulf Stream. Knowledge of the position of
the Gulf Stream is important to fishermen, weather forecasters, Coast
Guard search and rescue operations and many others. Some sources
of Gulf Stream analyses and position information are provided by the
NOAA CoastWatch program (http://coastwatch.noaa.gov) via http://www.class.noaa.gov