Active Sandals are sandals characterized by features to support the wearer in low intensity activities. Active sandals will typically have ankle straps for support as well as buckles, straps, or other such features for functionality instead of aesthetics.
About Waterproof:
Waterproof materials deflect water, and cause the article to not become bogged or soaked with water. Waterproof material is common in outerwear, footwear, and bags.