A quick description of the trip. You have to do three transfers before boarding the bus:
1. from hotel to bus station (pay for taxi out of pocket)
2. transfer from bus station to the pier (minivan >5 min drive)
3. pier to boat to the other pier (transfer your luggage from the minivan to the boat 2nd floor, then back to the bus at the other pier)
The whole trip took 6.5h total (noon to 6:30pm), from the bus station to the airport with two breaks in between; 10 min one soon after boarding the bus and a 30 min one around 4:30 pm for food.
Noticed that talker folks had a tough time fitting into the seats on the bus. Overall, not the most convenient transfer to the airport compared to other options available on the island, especially if you have kids, heavy rolling luggage, large group etc.