At least on the Ocean Reef, just press the 2nd stage purge button. Air will fill the mask and displace the water out the bottom vent.Wow thanks for the blunt response haha. The only reason I asked is because I cannot imagine having to clear a fully flooded FFM, but then again I’ve never tried one. Surely with that much water volume, it’s very very hard? I would have thought that they have some other way to do it like one way valve or something....