Of course, cost really depends on the size, but there are a number of yacht transport companies using heavy lift
ships that do this every day. Catamarans pose no special problems, they routinely handle superyachts with a beam probably wider than whatever catamarans you are thinking of buying!
The prices quoted by SandCrab are typical of what I have seen for a delivery
from Fort Lauderdale
. Because of US legal
issues, you will not find any ships delivering from one USA port to another, hence the need for a Vancouver or Mexico delivery
for USA East Coast
originating yachts. However, coming from overseas, yachts can be offloaded most anywhere the ships are scheduled to have a port call.
One of the larger service
is Seven Seas Yacht Transport. They are actually a kind of broker
for these services, they don't own the ships.