What pass would you recommend for a half day city tour in Hong Kong?

Actually, you are not advised to buy an octopus card for such a short layover. Just buy separate tickets for MTR, buses, etc. You may go to Ngong Ping 360 or Disneyland Resort during the layover. Remember to return to HKIA at least 2 hours before departure.

By the way, if you really want to buy one, the Standard Octopus Card is recommended. You need to pay HKD 50 as the refundable deposit, and HKD 100 as the minimum initial stored value.

Thank you very much Lydia.

I was hoping to see Tsim Sha Tsui but I have no idea how long does it take to travel by MTR from the airport to Tsim Sha Tsui station. Do you know how many minutes will it take from airport to CENTRAL or airport to Tsim Sha Tsui? Will I have enough time to return to the airport 2hrs prior to my connecting flight?

All the best!

To Tsim Sha Tsui, you may take Airport Express from HKIA to Tsing Yi Station. Next, change to Tung Chung Line to Lai King Station. Then, transfer to Tsuen Wan Line to Tsim Sha Tsui Station. The trip takes about 45 minutes.

To Central Station on HK Island, you may take Airport Express from HKIA to HK Station. HK Station is adjacent to Central Station. The trip takes about 25 minutes.

Yes, the time is enough! May you have a nice trip! :)