Everyone has their version of 'running away to sea'. Mine involves getting into the family car and going to Las Vegas or Reno, NV to shark the low-limit tournaments against the tourists for a living. (Not a very good living, I'd like to point out)
My friend Derick's 'run away to sea' fantasy has always been more literal: he wanted to run away and be a sailor. A number of different places around the world train sailors and provide a certification that allows you to get work as crew or captain on boats around the world.
Derick ran away to Malaysia to join and started a blog about his experiences. Check it out.