David, one thing to watch when airbrushing is water in the atmosphere (humidity), especially where you are, and at this time of the year when it's 30 degrees Celsius and 90% humidity. Does your compressor have a dryer or water trap in the air line? If not, then I suggest you fit one, or you will suddenly have blobs of water on your nice new, wet paint - not conducive to a good finish. I have owned a Badger airbrush for over 25 years, and it does a great job, although it is only a small one, and I have never used it to paint a boat - it would take too long. I generally use spray cans for boats, and lately I have been using the White Knight range from Bunnings with excellent results.
Peter.