Wottos, Blairs and Robs posts were excellent.
I used to jetski in sydney harbour alot. It was hectic for sure, even for the most experienced riders, it was certainly not a safe place for any novices. The govt ferry boats, old diesel types and the new jet boats literally would aim straight for you, and they wouldnt stop at all if u got in their way, or if they got in your way. I saw a bloke get run over by a 60 ft jet ferry, luckily he was able to dive deep enough and he didnt get hurt, but his ski sank, never to be seen again.
Jetskis n sydney harbour was always going to end with a ban so the ritchy people could enjoy breakfast wiothout jetskis. But the powerboats were twice as loud, work that out ! I know how fun going out to the oil tankers used to be as well, we used to ride our skis (I had a XP and a GTX Limited 3 seater - I would swap between skis depending where i took them, and my brother owned a XP and a 3 seater as well).
The oil tankers were huge. It was fun seeing just how big they were. The crews used to wave, and sometimes ask for a double. We had lots of fun. I used to ride the georges river system starting at Revesby and ride all the way to the ocean at botany bay via captain cook bridge, then out to the heads with the oil tankers etc. I did see my fair share of large white poointer sharks over the years as well. That used to scare the living shit outta you. These monsters were huge. It always reminded me not to fall off in certain areas, or u became shark food. Some people never even had a idea that sharks were even around. Fun times.
In QLD, the jetski stuff is much easier than the NSW laws, but u still have to play safe, and then u can have a absolute blast as Wotto said, and the jetski's are just sooo much fun. Definately my aim this year is to waterski and jetski alot more often, starting with the new ski I am just looking at.