covediver
Contributor
I do believe that closed-heel snorkel only; open heel scuba is one of those enduring proverbs and myths of diving. Decades ago when I learned to dive, that was the wisdom for colder-water diving. We were told that with the extra gear and weight that was involved in colder waters, that closed heel fins would not generate the power needed to move the diver efficiently thus causing greater effort and air consumption and that hard-soled booties would not work in closed-heel fins. Not sure that is the case in warmer waters, or even cold water anymore with the new materials and designs. Blade length, stiffness, and power developed by a fin design are the factors, not so much open versus closed foot pocket.