There are now 5-6 buses running between Pottuvil and Colombo, all travelling through the night and taking about 7 hours. Two of these are luxury ac buses and the rest are regular non-ac buses. It appears that one of the non-ac private buses can be prebooked at busbooking.lk (see the comment below).
Approximate departure times (usually to within 15 minutes):
Leaving Pottuvil to Colombo
- 7.00pm (private bus that can be prebooked).
- 8:30pm (private luxury bus with ac).
- 8:45pm (government bus).
- 9:30pm (government bus).
- 9:30pm (private luxury bus with ac).
Leaving Colombo to Pottuvil / Arugam Bay
- 7:30pm (two private luxury buses with ac leave from the Bismallah Lodge (opens in Google Maps) see note below).
- 8:45pm (government bus from central bus stand).
- 9:00pm (government bus from central bus stand).
- 9:30pm (government bus from central bus stand).
- 10:15pm (private bus from the private bus stand that can be prebooked).
Note: You can buy tickets for the luxury ac bus at the Bismallah Lodge in Colombo. The final destination of this bus is Akkaraipattu and there are only 10 reservable seats for Pottuvil.
For other general information on this route see the page Colombo to Arugam Bay Bus.