Hehe, Cash absolutely loves to swim. He always swims at my parents' house. I limit his swimming session though, because he gets so excited that he hyperventilates. My siblings loves to toss the ball into the pool and have Cash bring it back to them.
I get paranoid though, partly because of the hyperventilation thing and partly because Cash dives in so deep that the water covers his whole body, including his face. If the ball sinks, he will try to dive (while in the water) to get it and he won't get out of the pool until he gets it.
He doesn't have a lifejacket, but he isn't allowed to swim unattended and I am very strict with my siblings when they are playing with him. If he starts shaking or even slightly choking, the games are over.
I am happy that he swims and he really enjoys it, but like all things with Cash, I have to calm him down a bit and really control what he is doing. Otherwise he would swim all day every day!
Ps. After he started swimming, he seems to enjoy his baths more than he did before. He also swims in rivers and the ocean. He is a natural - he swims better than me and I grew up with a pool and water-loving parents!