VideoSecu High Sensitive Preamp Tiny Spy Microphone Audio Pickup Device Kit for Security Camera Sound Voice Monitoring Recording with 100 Feet Cable and Power Supply WUH -- More info could be found at the image url.
This is why you need this waterproof spy watch. The watch also has a built-in microphone to catch surrounding sounds. Smallest Pin-hole camera made especially for spy use. Waterproof, but it can NOT be used underwater.