Theres a thread on "The Truth about DiveMasters" over on SB, based on the general consensus, DiveMasters are in high supply with relative demand. The problem lies in the fact that dive ops often use instructors as DiveMasters, why use someone with less training when you can use one with more? Pay is crap and most of the time comes only from tips as a lot of people will DiveMaster for free in order to get experience/training. Basically, the only way to make a living in rec diving is instructor.