I've got an Air Asia flight to Surat Thani airport which arrives at 15.25 pm. Is it feasible to get to a hotel in Chaweng that same evening or do i need to stay a night in Surat Thani. I presume i would have to get a bus to Don Sak, then the ferry to Lipa Noi, then a taxi to Chaweng. Would travel time get me there @ 9 pm ?

Easy. But might be better to book at least one night stay at a hotel, you can then take your time & have a look the next day.

Easy as Roo says. Not much in Surat TBH except maybe some shopping... If you do the trip all the way then you can at least wake up the following morning in the knowledge that you don't have to rush anywhere followed by a swim then breakfast.

You will be able to purchase a joint ticket for bus and ferry on the flight.Buses are waiting at Suratthani airport and they get you on the last ferry. On the bus from the airport to ferry they can arrange transport from Nathon pier where you arrive to hotel again buses all waiting. This is very well organised between Air Asia and Pantip bus company should be in your hotel about 9.30.

How about hiring a car at Surat Thani airport and drive, can make it to the car ferry in time?