There are now 4 buses running between Arugam Bay and Colombo, all travelling through the night and taking about 7 hours. None of these buses have ac. It appears that one of the private buses can be prebooked at busbooking.lk (see the comment below).
Approximate departure times (usually to within 15 minutes):
Leaving Panama / Arugam Bay / Pottuvil to Colombo
- Panama 6:30pm, Arugam Bay 6:40pm, Pottuvil 7pm (private bus that can be prebooked).
- Panama 8:15pm, Arugam Bay 8:25pm, Pottuvil 8:45pm (government bus).
- Pottuvil 9:00pm (government bus).
- Pottuvil 9:30pm (government bus).
Leaving Colombo to Pottuvil / Arugam Bay / Panama
- Colombo 7pm, 9pm and 9:30pm (government buses from central bus stand, stop in Pottuvil).
- Colombo 10:15pm (private bus from the private bus stand that can be prebooked, stops in Pottuvil, Arugam Bay and Panama).
For other general information on this route see the page Colombo to Arugam Bay Bus.