Water Births

Who is planning a water birth or has already had one? I'm 15 weeks and I've seen 4 doctors so far. Two of them being water birth specialists. I was told yesterday I am now considered high risk and at this point they are refusing to give me a water birth. The only reason I can come up with is because I wouldn't be able to be hooked up to all the monitors? I have neuro & heart problems. They still said I could have an unmedicated birth. So what's the big deal if I'm setting in a tub of water instead of on the bed..? I'm determined to have this water birth one way or another.