I am building a new house, and have made provisions for my 23' chap.
However, the beam length is to wide. I will need to move the boat side
ways. I have seen a device that is used for cars to move them around,
called skates. Is there such an animal for trailers? Is there a rolling
plate available? Many thanks.

Are you looking for these?

Wheel skates work great for a car in a garage on a nice smooth concrete
floor. Is that where you'd be keeping the boat? Otherwise, how smooth is
the surface on which you need to move the boat?