Yes, it is possible for waterbeds and ferrets to peacefully coexist, but
with some precautions.
 
Bud, our second ferret killed our waterbed mattress one weekend I was out
of town on business.  Chewed the corner off.  Fortunately the bed had a
good liner so no great damage was done.  The mattress was over 10 years old
anyway, and I had been thinking of replacing it.  (Numerous patches in it
from an unnamed person in my house who used the bed to hold the straight
pins from a new shirt - stuck them into the bed so she could find them when
she was done.  <G>)
 
When we replaced the mattress we bought (as best as I can describe it) a
large quilted waterbed mattress "cover" that the mattress fit inside of (it
has a top, sides and bottom) and the quilted top zips up to completely
enclose the mattress.  When the fitted sheets were on the mattress and
cover, Bud couldn't even get to the zipper, let alone the mattress.  The
mattress is now over 5 years old and has not one tooth mark (or straight
pin hole).
 
Dick B.
[Posted in FML issue 2504]