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 major harbors and along heavily traveled coastal waters, but are not intended in any way to supersede or alter the applicable Rules of the Road. Separation zones are intended to separate inbound and outbound traffic and to be free of ship traffic. Separation zones should not be used except for crossing purposes. When crossing traffic lanes and separation zones use extreme caution. 

IMO AMENDED TRAFFIC SEPARATION SCHEME
Portions of the traffic separation scheme shown have been amended by the IMO. See IMO COLREG.2/Circ.64 and IMO COLREG.2/Circ.78 Annex 2. Please be advised that these portions have not been revised by the United States Coast Guard and that the corresponding changes have not been updated in the Code of Federal Regulations (33 CFR part 167). There are differences between the two traffic separation schemes and caution is advised.