Baby Cabana Going Swimming With Baby?

Going swimming with baby? - baby cabana

My daughter is almost three months. We thought of going to the beach tomorrow. Take the umbrella of the cabin and everything that is not against the sun and the child still being able to swim like. But I wonder when is the right age for the baby to swim with you in the water? And the sea or the pool better? I thought to take to swim 6 months - after the last series of DPT shots. He could not before?