A properly fitting mask should not leak, but snorkeling is fun and a big smile can cause a small leak. Sometimes hair stuck in the mask skirt can cause a leak too.

A purge valve allows you to eliminate water through the one-way purge valve without removing or tipping your mask. If your mask has a built-in purge just exhale normally through your nose. The water will drain out of the purge valve.

The purge needs to be at the lowest point in order to work properly.