8. Your VHF is not as secure as you perhaps assume.  Transmissions over VHF have gone 400 to 500 miles beyond the horizon.  PTs operating reasonably close to enemy territory or units can give away their position and valuable information by useless chatter over a VHF circuit.  And remember, you are not the only pebble on the beach.  Our planes use it extensively.  Unnecessary PT transmissions must not clutter up communications of a vital operating aircraft squadron.  You may think the air is clear because you do not hear any transmissions, but, remember, they may be receiving you several hundred miles away where they may be making a strike.  So do not depend on the term “line of sight” transmissions.  It is not reliable at all times; hence guard the use of your VHF set much as you do the TCS.  Jam sessions, razzle dazzle cowboy stuff, and hot shot vocalizing are all very amusing to you if you are a lunk head.  Just consider the harm you can do to yourself, your shipmates, and our aviators and you will be sure to knock off all unnecessary transmissions.  Even when another boat in your section cannot hear you, your transmissions may carry to out of sight areas where the enemy may be listening.

 

Transmission security for both radios is greatly enhanced by the use of follow the leader tactics, basic formations and courses established before leaving the base, and prearranged rendezvous points and times if the boats get separated.  When PTs operate in sight of land, special care must be taken in VHF transmission.  The Japs have many monitor stations on land and they have made many experiments with VHF type of equipment.