In order for you to understand the why's and wherefor's of your question read Dr. Benjamin Franklin's "Maritime Observations" (1785)and Matthew Fontaine Maury's bio "Pathfinder of the Seas", published out of Princeton.

The Gulf Stream has a lot to do with an answer to you, considered both by Franklin in his quest for timely delivery of mail in his position as Postmaster General and Maury's interests in his position in the Bureau of Hydrography, setting projected sailing times of vessels.