Not all hospitals are the same. Some have a lot of birthing equipment available and give you many more options than just a hospital bed to deliver your baby. You'll find birth stools, birth balls, and even birth tubs, at quite a few hospitals. If your hospital has a birth tub, or several, that still does not mean you will be able to give birth in the water. Why?It is possible that there will be no birth tub available when you go into labor, because another mother is using it. Many hospitals have birth tubs only for labor and not for the actual birth. Even if you are encouraged to use the tub for pain relief while you are having contractions, it is possible you will be asked to get our before you start pushing. Depending on your hospital's policies, you may not be able to labor in the tub once your water breaks. Some doctors hold that this increases the risk of infection.
These are all points to discuss with your healthcare provider in advance. Some hospitals do allow under-water births, depending on where you live, and many don't have tubs at all! If you can't use a tub or there is no tub, you may still be able to have showers during labor. And of course, it may be good to keep in mind that laboring in a tub means you will not be able to also get an epidural.