Full-face masks have real safety benefits when designed well: covering the nose and mouth lets you breathe naturally instead of biting a mouthpiece, and a good dry-top and drainage system keeps water out. The main risk with poorly designed full-face masks is exhaled air pooling and raising CO2 levels inside the mask. Cressi's Prince addresses this directly with a dual-channel system, lab-tested to separate inhaled and exhaled air. Both the Prince and Baron are built for surface snorkeling only, not scuba diving, where pressure changes can affect performance.

No, a snorkel mask only lets you breathe while your head and the top of the tube stay above the surface. Once you duck under, water fills the tube and breathing stops working the way it does on top. Snorkels aren't built to work at depth either: water pressure on your chest makes it physically difficult to inhale through a tube more than a foot or two underwater. For actual underwater breathing, you need a scuba regulator and tank, not a snorkel.