Meet the HybridSack: a hybrid water and sand weightlifting bag that lets you exercise at the beach and anywhere else for that matter. It comes with multiple grips that let you perform a wide variety of workouts. You can fill this with 77lbs of water or 120lbs of sand.
This weightlifting bag has a portable design, so you can use it anywhere. It has a waterproof cover, so you can clean it with fresh water.