Having a baby? well i recommend a water birth, it is natural , better for mother and baby, relaxing passage of newborn into our breathing world. It is a way of pain management ( they have reported that it lessens back pain) weather you want your baby to come out under water or just labor in it before your baby comes. It also lowers the chance of getting an episiotomy or tearing due to the warmth of the water and the support giving you an intact perineum which we all love. And you may get in it after 5cm due to it relaxes mom's soo much it might even stop your labor. Some providers may ask of you to come out to deliver your placenta outside to better assess you.