We took a trip on a super-fast jet boat in Sydney - it was amazing! This one, operated by Atlantic Adventures, looks like it's probably just as much fun.
I considered the trip (instead of the deathly-slow Steamboat Vicky trip) but we wanted to take our two nieces out on a ride and this one (while cheaper and longer than the Australian Thunder Jet) was more than we could spend on the trip.
Take a close look at the back of the boat - see the guy with his arms raised? Looks super-happy hey? :D