FATSAC Floor Fat Sac Ballast Bag - 500lbs - Black [W700-500-BLACK]Floor Fat Sac Ballast Bag 500lbs Black Designed to sit on the floor of v drive boats, the FatSac 500 lb. Floor ballast bag adds a significant amount of weight to the middle of the boat to help create a more sizable wake for your riding pleasure. Needing that extra bit of wake to build your wake up or the rear lockers full of gear and need to place ballast elsewhere? A floor ballast bag is a great option for adding a good amount of weight in v drive