Jo-Anne,
In 2004 I travelled to Maui and went Snuba diving. Obviously we were attached to the boat and did not go nearly as deep as scuba divers might, but, although I was worried about the dry mouth, I had no problems and no discomfort at all breathing through the device.

Good luck,
Danny G.

Stage IV Base of Tongue SCC
Diagnosed July 1, 2002, chemo and radiation treatments completed beginning of Sept/02.