Walking barefoot by the pool is comfortable, but be aware of a few things.  It is known that there is an increased amount of the virus that causes warts, and if you are wearing slippers or sandals then your skin bare skin is less exposed.  There is also the chance of picking up the fungus that causes athlete's foot and fungal nails. In addition, there may be foreign objects around the pool, and you want to make sure your skin doesn't get scraped. So it is better to wear sandals around the poolside, and even consider water shoes if they are comfortable.