Hi Pauche. I haven't heard of any through trips via Ha Tien yet, such as the trips via Moc Bai and Chau Doc, but it doesn't matter. Getting from Phnom Penh to Kampot is the easiest thing in the world. Buses and share taxis operate every day of the week. It is a three hour ride to Kampot. In Kampot, simply ask any of the moto drivers to take you all the way to the border crossing, called Prek Chak on the Cambodian side. That one way ride on the back of a moto can probably be done for well under 10 dollars. The road between Kampot and Kampong Trach seems to be paved all the way now. Otherwise, get into a share taxi between Kampot and Kampong Trach and take a moto from there to Prek Chak for maybe 3 dollars. No problem at all to get from Phnom Penh to Ha Tien in one day at this point, maybe even in half a day if you got up early enough.
About the boat ride between Ha Tien and Phu Quoc Island, there is a boat dock right behind the central market in Ha Tien, but foreigners may still be forbidden to use that particular boat. It is because that particular boat crosses contested territory on the way to the villages on the northern tip of Phu Quoc. If this is still the case, any moto driver in Ha Tien will take you to Ba Hon, about 30 minutes to the south of Ha Tien. Small fishing boats converted into freight boats depart from there every morning for usually Ham Ninh, on the eastern side of the island. Motos will take you from there to anywhere on the island. The best beach on the island is called Bai Kem, just to the south of Ham Ninh, but most people stay on the long beach to the south of Duong Dong on the western side of the island, probably of the sunsets and the greater number of places to stay.
Getting back to the mainland from Phu Quoc, you can return to Ba Hon, but a better idea is to take one of the bigger ferries to Rach Gia. Of course there are regular buses from Rach Gia to Saigon, but if you want to tour around a bit on the way, it is easy to get a moto driver in Rach Gia to drive you to for example Can Tho. Spend a night there and then get one of the Can Tho based moto drivers to take you to My Tho, for example. From My Tho, it is less than three hours into downtown Saigon on a motorcycle. In short, if you are not in a hurry, you can get the local moto drivers to take you all from Rach Gia into Saigon. Highly recommended. If you find a good driver, you will probably end up seeing a lot more than you know about along the way.
For other ideas, here is a recent post about the crossing from a guy who lives in Phnom Penh and who gets down to Kampot and thereabout fairly regularly. While you are at the border station itself, you might ask the border guards about taking motorcycles across. Maybe that too is now possible??? Enjoy your visit.
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The much anticipated, oft rumored, magical mystical Cambodia/Vietnam border crossing near Ha Tien is now open to foreign travelers. CONFIRMED. Yes, it's true. The coveted Ha Tien crossing has been wrongly rumored open more times than Pol Pot was reported dead. But this time it is true. Ha Tien is both officially and truly open and functioning.
Until the end of last month Ha Tien was a locals-only crossing - no foreigners allowed. As such, the Ha Tien crossing was the last road block in the overland coastal travelers trail from Thailand, through Cambodia and into Vietnam. In the past, from Kampot/Kep, beach-trailing overlanders were forced to detour north to the Phnom Den or Chau Doc crossings into Vietnam and then work their way back south to the coast. But as of May 24 2007, the Ha Tien Crossing near the coast - officially known as the Prek Chak crossing in Cambodia and the Xaxia crossing in Vietnam - became an operational international border crossing. Now travelers can roam from Koh Chang Thailand through the coastal towns of Cambodia and on to Phu Quoc Vietnam without ever having to leave the beach road.
Guesthouses in Kampot and Kep are still giving mixed reports, some saying the Ha Tien crossing is open, others remaining justifiably skeptical, saying they are not sure, but the Khmer motodups and tour operators in town all agree that the crossing is now open to foreigners. For definitive confirmation, I rode out to the border crossing myself today and got it from the horse's mouth. There is a brand new immigration building at the border and the immigration cops were ready and happy to talk to me about their new international crossing. They told me the border is now open and that they have been seeing 2 or 3 foreign travelers a day for the last couple of weeks. They also said that the crossing is open from 7AM - 6PM and, importantly, that neither Vietnamese nor Cambodian visas are available at the border. You must get your visas in advance. They predicted that they would be able to issue Cambodian visas at the border within the year. He also claimed that the Cambodian e-visa could be used at the Ha Tien border crossing, but I have not confirmed this.
The road from Kampot/Kep to the border crossing is, for the most part, in good condition, taking about 1h15m from Kampot to the border. I checked out two routes to the border. 1) Route 33 east from Kampot to Route 31 at Kampong Trach town. This is also the road from Kampot to Kep. Just bear left at the White Horse monument and continue on to Kampong Trach (instead of bearing right to Kep). This leg is all in good condition, sealed, about 40 minutes. Turn south on Route 31 in Kampong Trach. All but the last few kilometers to the border are sealed. This leg takes about 35 minutes. 2) Route 33 east from Kampot. Bear left at the White Horse monument and continue about 10km more to a good dirt road. This leg is in good condition, sealed, taking about 30 minutes. Turn south at the dirt road and continue about 15km+ to the border. Hardpack dirt that will probably flood in the wet season. Now, in the very early wet season, this leg took about 35 minutes. Both routes may deteriorate in the later wet season, but #2 will probably be much worse than #1.
The Ha Tien destination is so new that the tour operators and motodups in Kampot haven't settled on a standard price for a moto to the border for foreigners yet. I talked to four different people and was quoted $5-$15 for a motodup and $10-$25 for a tuk tuk. The real price will probably settle around $8-$10 for a motodup and $15 or more for a tuk tuk.
There is not much at the crossing point. Checkpoint shacks and the new immigration building. Smugglers trail opposite the checkpoint servicing what seemed like a constant stream of bicycles overloaded with crates Hero cigarettes. A few little restaurant/coffee shops and some small houses along the road. No foreigner services. Nobody except one of the immigration cops seemed to speak English. No obvious waiting onward transportation. Maybe it's there but I didn't see it.
A guy in a coffee shop on the Cambodian side of the border told me that once you are on the Vietnamese side, a motodup to Ha Tien town costs about $2-$3 and to Ba Hon a bit more. he said you can catch a boat to Phu Quoc from either town but that Ba Hon was better.