Why no Residential Fridges?

[nebster]

Hey all,

I'm a total newbie, starting the research for living aboard a few years from now.

My family's been living in an RV for the past year, and so I have become well-acquainted with the systems we have. I am now trying to translate my understanding into things more appropriate for at sea.

The first thing I can't figure out is, why are there no residential fridges in boats? RVs basically moved to these a couple years ago, I suppose in part because they are so efficient now and in part because the Norcolds and Dometics of the world were so notoriously sucky. (And because with induction and microwave convection cooking, one can get rid of propane entirely and make things a lot simpler.)

So... is it just a space issue? Could it be something with orientation/motion? Or maybe rust and corrosion?

Thanks for clueing me. And be gentle, first post.