TRAFFIC SEPARATION SCHEME
One-way traffic lanes are RECOMMENDED for use by all vessels traveling between the points involved. They have been designed to aid in the prevention of collisions at the  approaches to Boston Harbor, but are not intended in any way to supersede or alter the applicable Rules of the Road. The Separation zones are intended to separate inbound and outbound traffic and to be free of ship traffic. The separation zones should not be used except for crossing purposes. When crossing traffic lanes and the separation zones use extreme caution.