Flotilla by Daniel Haight

With rehab behind him, Jim is exiled to a seasteading colony off 
the coast of California with his estranged father, Rick. Together
they live by their wits, scamming seafarers until a national disaster 
rocks the nearby mainland. Rick is forced to assist with rescue 
operations, leaving Jim behind.

All Jim wanted was a chance to put some bad choices behind him 
and bond with his father. Now, he's dodging drug lords, police, and 
angry colonists while terrorist attacks erupt only a few miles away. 
Is this the life a fifteen-year-old should lead?