Waterbirth means a gentle birth for both moms and babies. Water provides comfort, bouyancy, and relaxation. Laboring in the water reduces the sensation of uterine surges (contractions), shortens labor, and reduces vaginal tearing. Most moms have what I like to call the "Ah" reflex when they get in the water during labor. As in "Ah, this feels so good!" Most women find the water to be incredibly comfortable and don't want to get out. Surges are easier to handle. Labor also tends to progress more quickly once the mother is submersed. Being born in the water is beneficial to your baby too. It allows your baby to gently transition to life on dry land. The bouyancy of the water often empowers parents to receive the baby themselves. Your baby will probably think they've just graduated into a much larger womb! 

Yes! The biggest worry most people have is of the baby drowning or trying to breathe while still under water. Remember that the baby is floating in water throughout pregnancy. The stimulation to begin breathing air is the sensation of cool air hitting the baby's cheeks. Since the baby emerges into warm water, they do not breathe until they are brought out of the water shortly following the birth. The baby is still connected to the umbilical cord and is receiving oxygen from mom to help complete the transition. Shortly after the birth, the baby is gently brought to the surface (usually by the parents) and breathing begins.