Shalom, Dalia!
I am responding to your concern about waterbeds, and I believe that a
firm relatively small or non-existant waved bed is perfectly safe. I
breastfed both my sons in a soft-side waterbed, which is shaped-like and
feels a lot like a regular soft mattress.
My husband and I always kept the baby in the middle, and made sure that
the head of the bed was close to the wall. We never had a problem...
Debbie Albert, Ph.D., IBCLC
Tampa, FL