One way is ONLY for the diver to have and a track official ONLY to talk to them announce going green, where they line up, caution is out, move up and hold your line your being lapped. Track must have transmitter to do so, some require it.Kind of new to this, so an honest question on this subject. I understand two way radios are illegal, but you mention one way. Are they legal, and if so, which direction?