This is not for those who fear sounds of underwater machinary
I recorded the wave machine on voice recorder on interest purposes I have with the machines.
The Machine was recorded in:
Left Plenum Chamber aka Caission or Air Chamber
Middle Plenum Chamber
Underwater just near to the rope
This is not recommended with expensive equipment
Sound differences will vary on each recording of the same machine. Recording from the Left Chamber will I believe hear the valves, motor running.
Middle Chamber may sound a bit intimidating to some people. You will hear Hissing (Air), Whooshing Sounds or Like Tardis, I believe this is Air being blown in as there is pipes in the plenum chamber too or it could be water being pushed out. At time of the whooshing noise is when waves are being made. You will hear the other blower power up this can be heard underwater as a stronger hissing sound.
Underwater - Similar Sounds to the middle Chamber but not in the Wave Machine