The Irago traffic route connects Ise-wan and the pacific ocean. Many ships in Ise-wan use radio communications of VHF band. The VHF radio communication may be increased after the AIS is equipped. The AIS is used on many coastal and ocean going vessels. These information of AIS and VHF radio communication are used when a deck officer decide the own course and speed. However, the reason and background are unknown how the changing his course and speed. This paper describes the result of observing the Marine traffic in Ise-wan by AIS and VHF communications. The authors designed and built the AIS and VHF radio communications recording system. The AIS and VHF Radio communication are received at the Toba College of Maritime Technology. The using VHF channels are almost 16th, 6ch and coast station. The ship to ship communication is 15%. The point of calling by radio is usually located along a traffic route of Pacific to Nagoya. The distance between two ships are far in order of passing, crossing and counter. The VHF radio communication between onboard deck officers expands a permissible range of their safety which shows decreasing SJ value in that case.
