a bag for conveniently holding fish in water safely and for weighing the fish during a fishing tournament . the bag comprises a polymeric material which is water tight but allows oxygen to pass into the bag and carbon dioxide to pass out of the bag . the bag is fold - able but when filled with water , the bag has no right angle corners where fish tend to congregate and crowd one another . an optional hoop is provided which integrates with the side wall of the bag and will force the shape of the bag to remain in a preferred more rounded configuration . one embodiment includes a sealable closure at the top to fixedly contain the water and fish .