Full Face Snorkel Mask Test and Dry Top Test: Comprehensive Analysis

Full face snorkel masks have grown popular for their natural breathing, better visibility, and anti-fog properties, but safety concerns exist. NIH research papers have documented issues with CO2 rebreathing and water intrusion resistance. In this video, Dr. David Zhang provides a detailed analysis and demonstrates how to test your mask for potential problems.

Understanding Mask Design

Every full face mask has two pockets: the eye-pocket and the oronasal pocket. Understanding the separate inhale and exhale paths, and the location of unidirectional valves, is critical for safety. The video traces these paths for two different mask models using colored shoelaces for visualization.

The 3-Step Mask Test

Step 1: Test unidirectional valve function. Step 2: Test the face-to-mask seal. Step 3: Verify that the breathing paths work correctly under conditions simulating actual use.

The 3-Step Dry Top Test

The dry top mechanism is designed to seal the snorkel when submerged. The three-step test verifies that the dry top seals properly, opens fully when above water, and drains correctly when water enters.

Safety Awareness

Full face masks should not be used for deep diving because equalizing ear pressure is not possible. They are designed for surface snorkeling only. The video references two NIH papers that document the specific risks.

For more outdoor activity content, see Dubrovnik, Croatia and Carnival Breeze cruise ship.