floating island

Bought this because I pictured myself going too lake and relaxing on it. unfortunately unlike the picture of two women in bikinis too sell it the warning on back says you should use it with a life jacket. why you need it then. would be great too take too wet and wild since the waterpark charges you extra for tubes why not bring this instead. or for the adventurer that's a decent swimmer and knows they can swim without a lifejacket.