Barrack Street Jetty is the busiest in Perth and close to Elizabeth Quay. As such, it is really good for pick-ups and drop-offs, but not that good for long term parking. The traffic system there is one-way. For that reason, most passengers, including our staff, use the public parking lot opposite the Supreme Court Gardens where you can almost always get paid parking.
Note: leave about 15 to 20 minutes extra time to drop off your friends, food and drinks and then go park your car. It will only take about 5-10 minutes to walk back from the parking lot to the Pier 1. You can even through the riverside walkway in front of the pub.