We actually anchored off Port Douglas, which is about an hours north of Cairns. Loved the town, had lunch ashore but had to dodge rain showers. There was only ships boats on the return and a choppy swell so a bit rough coming back and took a couple of small waves in through the side door of the boat.
Shuttles were quite good, the town is close to the port and we shopped a little, picked up goodies in Woollies, had lunch and a beer in the main street pubs, free WiFi in the mall and had fun. We were a little delayed getting off the berth as there was a huge Jellyfish invasion which blocked the cooling water intakes. Lovely lightning storm accompanied us out of town, amazing.
We were 2 days in Hong Kong. Got off at the container terminal and bus into town. We elected to stay there for the light show and the ship repositioned at 5pm to anchorage so caught the tender boat back at 9pm and went ashore again the next day. Hong Kong is huge so attend the port lecture beforehand if you are wandering around like us (and don't forget to take heed if the 2nd days tender pick up is at a different area than the drop off, we had 2 pax who did that and had a very expensive trip to rejoin the ship in Taipei.) Hong Kong is also part of the Chinese republic so if you don't leave the area, you are OK, but if you go to Macau or the mainland China, you will need a multi visa but if you stay in Hong Kong area, you will only need a multi visa if you enter a Mainland Chinese port and then go somewhere else like say Japan and then re-enter China.
We knew about the "Big Red Bus" tours from London (its the same company). You can get a 2 day pass which includes ferry rides. Well worth it. Hop On/ Hop Off. Great for shopping and sightseeing. Good service, English commentary and they supply earphones and ponchos which are always useful.