If you still want a baby with him, you're just going to have to either keep arguing your point or give birth without him and have another birth partner - one who is on your side. Please do not let him win on this one, he's simply not right and he's not the one who has to go through with it.
I had a water birth and while it was obviously still painful and a lot of hard work - I honestly found being in the water brilliant and would highly recommend it.
I was only in the pool in the labour ward for the last couple of hours - I spent a good 14 out of the 16 hours of my labour at home on the sofa / birthing ball.
Also the technology these days is brilliant. I had wireless monitoring strapped to my bump so that the baby's heart rate could be safely monitored in the water just as it would be "on dry land".
You can obviously get out at any stage. At one point they were worried the baby was breech so I popped out of the pool onto a bed in the same room, they got a doctor in who performed an ultrasound scan right there and then in the room, they confirmed the baby was in fact head down and then I was allowed to simply get straight back in. Even though I had a water birth, the baby was monitored exactly as he needed to be.
I do appreciate that some women plan water births and then for various reasons they can't have one, but it seems ridiculous to me that your husband is ruling one out altogether.
He is being very ignorant, stubborn and selfish.