Just use your common sense and avoid areas were there are surfers, windsurfers, kiters, swimmers or people having a nice peaceful picnic on the banks of the river etc.
None of us will be impressed at how fast you can go or how good you can ride so you don't need to do it in front of an audience.
I have had several bad experiences with jetski's and absolutely hate them.
Once I was out at Little Island enjoying a surf midweek with only myself and a mate out, it was perfect a decent size swell, glassy as and only the sound of the waves crashing......Bliss..... until a jetski appeared.

He could have gone anywhere along the reef that streches for miles to jump the waves but no he hung around within metres of us scaring the **** out of us at times as he jumped over waves and on one occassion he crashed down within about a metre of me.

What would have been a perfect day was ruined by noise, fumes and fear.
Please be considerate and think of others.