To get less water in the snorkel I attach it to the mask strap in such a way that it points directly up when I'm face down in the water. I see everyone attaching the snorkel on the mask strap right behind the ear if not even over it. The snorkel ends up pointing forward, which makes it lower, and the snorkel opening pointed at head on waves. I attach my snorkel at the mask strap split on the lower strip. and make sure the snorkel is perfectly vertical when I'm looking down. I guess head shape will dictate to some degree where ideal placement is for different divers. Generally I see divers not pay attention to this detail and their snorkel is not positioned straight up.
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