Train 31 from Bangkok to Hua Hin is the most comfortable and clean service operating on the Thai Southern Railway Line, as it operates with the new Chinese made carriages.
This Special Express train is not cheap compared to other services on this route, but if you want to experience these nice new carriages, you have to pay extra.
All carriages are air-conditioned.
2nd Class seats from Hua Lamphong Station to Hua Hin cost:.
1st Class seats from Hua Lamphong Station to Hua Hin cost:.
Since this is only a relatively short journey to Hua Hin, tickets may be hard to come by if you leave your booking too late.
Tickets for trains in Thailand now go on sale 90 days before departure - However, that is for journeys of over 60% distance of the route.
Anything less than that and tickets are only sold 30 days before departure.
From Bangkok to Hua Hin, that means you can buy tickets only 30 days in advance and at very busy times of the year, that will mean most of the seats will already be sold by the time the tickets go on sale to Hua Hin (the BangkoK to Hat Yai route is a very popular train journey).
If you want to book seats on this train, try booking online as soon as the tickets become available.
You can also try using the ticket agent 12go, as they will take your booking for any period in advance and then buy the tickets for you as soon as SRT make them available for sale.
Another option rather than booking online, is to visit the advance booking office / ticket counter, of any of the larger train station within Thailand.