noun
water ball; water walking ball
A large inflatable sphere that a person can climb inside to walk or roll across the surface of water. Often seen at amusement parks and resorts.
夏休みに、湖でウォーターボールを体験した。
During summer vacation, I tried a water ball on the lake.
ウォーターボールの中に入ると、まるで水の上を歩いているみたいだ。
When you get inside a water ball, it feels like you're walking on water.