Could you live on a boat?

I know I mentioned before about how insane housing prices are in this area.  Before M and I moved here he mentioned to me about buying a large boat/yacht to live on.  My first thought was No, but now it is starting to seem like a good idea.  This is the only time in our life we would ever be able to do it.  We have to clear some debt before we will seriously begin to look into it.  You can now get boat loans for around 20 years.  The price range we would look at would make our payments a couple hundred dollars a month.  If we were to buy a home that would be a couple thousand a month.  If we sell our home and clear most of our debt we could live on the boat for a year and pay it off.  That would leave us with a fun toy and then we could go buy a house.  This is definitly something that would not happen for a year or two, but it is a possibility.  I LOVE the water and being on a boat.  I could totally move to and island or coastal town.  We have made friends here who have a 300sq ft apartment and a 40ft yacht.  If you havn't been to DC before the Potomac River runs around it and leads into the Chesapeake Bay and then into the Atlantic.  It will be good to see how our friends like it.  They have said there is a community of families who do this at their dock.  I can't imagine doing it with a big family, but what do I know.  So my question for you guys is..... Do you think you could live on a boat?  Here are some pictures of some possibilities:

Photo from johnnyjet.com

Photo from yachtsray.com

(in my dreams)

Photo from yachtcritic.info