@gtwilson In this case, it actually makes financial sense. He's always wanted to live aboard a sailboat, and since he'll be paying cash for the boat, all he has to worry about is the slip fee and maintenance. He'll be living at the (very nice) harbor in Ventura for less money every month than I'm paying for my mortgage three miles away--and I already have about the lowest cost of living you can have on the California coast, since we bought at the bottom of the market. And he can go sailing on the weekends. :-)
And even better, I can go over and sit on his boat and drink his coffee/beer/whatever when I need to get out of the house.