The Wireless-LAN was developed and Wired-LAN substitution from the field which the space where it is restricted is special it used. But, from the field which is various the use is attempted to listen to recently. The shedding of blood which the oceanic accident which occurs recently5 year for is principal is The GMDSS with the formation vessel which is managed with agreement depends here upon and it is a collision of the small-sized vessel which is not managed. Cause the Facilities for the safety-communications system is not introduced is the actual condition in poverty of the small-sized vessel. In this study, recently with the AIS where becomes the introduction it proposed similar function the system which is cheap it does.