The breathing port isolation apparatus includes a housing, valve, and actuator to enable a diver to isolate a breathing port of a snorkel or dive regulator using a single mouthpiece. The housing is configured to seat the valve and actuator and releasably engage a mouthpiece and dive regulator, which provides the diver with a continuous flow of air through the mouthpiece without having to transition between multiple regulators or breathing ports. The valve includes a piston and enables linear movement between the first and second port. The actuator enables the diver to depress a push-button and transition the actuator between depressed and extended positions, which correspond to the first and second breathing ports.

A communication device includes a mouthpiece intended to be worn in the mouth of a subject including an acoustic conduction plate intended to be bitten by the user; and a vibrating element configured to convert an audio input into an acoustic output, the vibrating element being coupled to the acoustic conduction plate so as to transmit said acoustic output to the plate.