I've tried the Ocean Reef snorkel mask and thought that it worked well. Inhalations obviously come down the snorkel tube and across the front of the mask keeping it clear of fog. Exhalations are directed out the bottom of the mask right in front and below the mouth, also expelling any water. With a proper fit I don't see a problem with CO2 buildup. Again this is with an Ocean Reef mask, I have seen a few of the knock-offs and they look very similar to the OR mask but I didn't try them on.
Edit: I did find 1 of two bad reviews in the linked article funny. Not sure if it's supposed to be a joke...or if it's the times we live in now!
“Snorkel works fine until you go under water, then it’s as though the valve at the top gets jammed and it’s like breathing through a straw,” E.G. Bradlee said in his July 27 review.
Edit: I did find 1 of two bad reviews in the linked article funny. Not sure if it's supposed to be a joke...or if it's the times we live in now!
“Snorkel works fine until you go under water, then it’s as though the valve at the top gets jammed and it’s like breathing through a straw,” E.G. Bradlee said in his July 27 review.