Those living on Samui without a full time visa arrangement find themselves having to do a visa run from Samui. This applies to those with a non-imm visa (three months) and those on 30-day tourist visas. Now that the immigration department have limited visas for overland entries to 15 days it hardly seems worth the effort. At the local immigration office in Samui, you can extend you 30-day visa once for 1,900 baht, which gives you another 10 days.
The most practical visa run option on Samui is to fly to Penang or Kuala Lumpur from Samui with Firefly Airways. With flights almost daily, this budget airline belonging to Air Malaysia have reasonable rates online, making it feasible. The Thai consulate in Penang is generally efficient at issuing 60-day tourist visas, but tend to be more sticky about paper work for non-imm visas. The former can be turned around in a single visit while the latter normally requires more than one visit.
The old traditional route for a border run was to Ranong on the Myanmar border, where you skip over to Victoria Point for an hour or two. No one runs a Samui visa run service as far as we know. The overnight excursion requires catching a ferry to the mainland and transfer to Surat Thani bus station for a bus to Ranong (2 hours +).
Once in Ranong, you need to check into a hotel, and then proceed to the immigration office to get ‘stamped out’ of Thailand before moving on to the pier three kilometres away. From here catch a short boat ride over to Myanmar. It delivers you to the immigration office, which retains your passport and US$10, and you need to come back after about an hour or longer. Therefore you should get on the next boat and go into Victoria Point.
Upon returning to pick up your passport, you then catch the boat back to Thailand where you will get a fresh stamp as you disembark and pass through the border control. They will probably ask to see proof of 10,000 baht in your account, so have this prepared. They generally don’t issue more than three consecutive entry permits in a row any more.
The transportation to and from Samui is about 500 baht and takes around five hours each way. You will need about two to three hours to make the Burma trip, hence an overnight stay is necessary in Ranong.