Also, to do away with things inherent to in mouth regulators like dry throat (from beathing dry air) or a "fogged" mask, you might also consider a full face mask. The Neptune has a kit that allows using an existing regulator (like from Aqualung, Mares, Scubapro, etc.,.). With a full face mask you can breath in and out of your nose, instead of your mouth. One other good note with a full face mask is, if for any reason you "pass out" underwater (ie. over narced, bad air mix...) you can't aspirate water from an "out of mouth" regulator. I think the Nepture full face masks also allow two regulators to be hooked into a single mask increasing the air flow capacity ... i'm not sure what this would be used for other than exerting yourself more than normal while underwater. Next year, i'll be investing in two sets of Neptune's with two way underwater communications. This will be really nice, especially with a base unit on the surface - allows me to communicate with others at the surface also.
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Mike.