Understanding these numbers

[Anthony L.]

I picked up a book " The Wall Street Journal Complete Real estate investing guidebook."  Looks good so far, but I am trying to wrap my head around some math in here.  If anyone could please break this down for me. 

When evaluating if buying a property is the best use of money the author states 

"Do the math:  If you buy a $300,000 house with a 95 percent loan at 6 percent, and the house appreciated at 5 percent annually, you're just treading water."  

$300,000 House
Loaned:  $385,000
Downpayment: $15,000

6% of $300,000 =  $18,000

Those are the specs I can pull out from this statement.  Very confused on how the would be owner is treading water.  If anyone can break this down for me, thanks!  I am assuming the 6% interest may be the annual cost of interest on the loan... Thanks for the help