Saturn is the least dense planet in our solar system. It's only 1/10 as dense as Earth and about 2/3 as dense as water. If you're less dense than water, you can float.
However, Saturn is 95 times as massive as Earth. It's the second most massive planet after Jupiter. Still, the force of gravity on Saturn is only a little more than on Earth. A 100-lb object on Earth would weigh 107 lbs on Saturn.