In Washington state, for commercial divers, there are only 2 types of diving:
Air and Mixed gas.
For Scientific divers there are:
air and nitrox
"what is mixed gas" most definitely depends on who you are talking to and the context.
Air and Mixed gas.
For Scientific divers there are:
air and nitrox
"what is mixed gas" most definitely depends on who you are talking to and the context.