BY POLLING POLICE DIVERS AS TO THEIR PREFERENCES FOR DIVING COMMUNICATIONS DEVICES, THE AUTHOR DETERMINED THAT THERE IS NO SINGLE SYSTEM PRESENTLY AVAILABLE TO MEET THEIR REQUIREMENTS. HE FURTHER CONCLUDED THAT THE SINGLE MOST IMPORTANT IMPROVEMENT THAT COULD BE MADE IN UNDERWATER COMMUNICATIONS IS A COMBINED MASK/MICROPHONE/ EARPHONE DEVELOPMENT, TAKING INTO ACCOUNT THE FREQUENCY CHARACTERISTICS OF MASK CAVITY AND THE DESIGN OF A MICROPHONE TO MATCH THESE CHARACTERISTICS. THIS WOULD DEVIATE FROM THE PRECEDENT OF MASK AND MICROPHONE MANUFACTURERS WORKING INDEPENDENTLY OF ONE ANOTHER. (AUTHOR ABSTRACT MODIFIED)...KAP