There are more jet ski fishermen in NZ than yakkers. There is also a fairly good size following here as well. It is fun but has it's own drawbacks. Like the fact that there are so many asshats out there on pwc that it comes with an immediate stigma of "one of those". Thus the introduction of laws like the no PWC after dark or before sunup law in California. They apparently do not enforce it tightly right now, but as with everything, one jackass can screw it up for everyone.
Also a concern is to b sure you have a partner or epirb as offshore distances might not be within radio range of another vessel if something goes wrong.
Catalina and tuna are well within range of most of today's 4 stroke motors, making the MLPA closures a good reason to start researching these guys!
A great site with alot of helpful people...
http://www.jetskisportfishing.com/