For benefit of INDIAN PASSPORT holders, VISA FREE travel to Phu Quoc.
1) You must have same day connecting flights to Phu Quoc, both ways. I.e. you cannot stay in HCM overnight without a Visa. Indians are not eligible for Visa on arrival either, so be careful while booking. Allow at least 1.5 hour between flights to avoid chance of missing the connection as immigration formalities take time.
2) Have your entire itinerary printed out showing all flight tickets, hotel bookings.
3) Dont throw away your arrival boarding pass for the flight landing in HCM.
4) Go straight to the Landing Visa counter, and tell them you are going to Phu Quoc.
For us the officer there along with a airport staff lady helped us in the process. They took photocopies of all our documents/passports. Make sure to tell the staff what time your connecting flight is in case you are short on time. For us, the airport staff helped us check-in on the HCM-PQC flight even before we had gone through immigration because our flight was in less than 1 hour. They asked us to email photos of the boarding pass after we collected them from the domestic terminal check-in counter (not entirely sure why, but we did that nevertherless). We had to wait for about 30 mins for the whole process whilst a lot of back n forth happened amongst the immigration & airport staff. After immigration, the domestic airport is about 5mins walk on the right after you exit (terminals are not connected internally).