Originally Posted by craz

sounds like youre heading by Williamsburg, and maybe even the Brooklyn Navy Yard since tehres alot of businesses there

The B train wont be of any help, the J would be best but you can only catch it DownTown and get off at the Marcy station. Or take the F to York St if the Navy Yard is where youre heading. Either way once you get off youd do best hailing a car service since there are few if any Yellows to be found in Brooklyn and they wont want to do a local trip

Or check out the Wiki on how to take the Path Train to Lower Manhattan and grab a Yellow cab from there