It's okay to put heavy things in it!
Not just snorkeling equipment
A Crete Mesh bag for carrying scuba equipment.
Duffle type and mesh material makes it very easy to drain water.
As it is foldable, it can be stored compactly when not in use.
Uses YKK zipper.
It is convenient because you can wash it with fresh water and let it dry as it is with the tools in it.