Touristic transfers to the island of Koh Lipe operates only in the months not subject to the monsoons, that means from november to may, the only pier where ferries run the year-long is Pak Barra. Ferries leaving from Pak Barra stop briefly in Ko Tarutao or in Koh Bulon before reaching Koh Lipe, and take about one hour and a half and cost 450 Bath, plus you have to pay another 200 Bath entrance fee to the Ko Tarutao National Park, and also another 50 Bath for the longtailboat taxi to the beach were you're going to stay.
But "How to get to Pak Barra?" You can decide to reach Satun by bus and from there, take a minibus, leaving directly from the bus station, and in an hour you'll be in Pak Barra. You can buy the "bus+ferry" tickets directly at the bus station. We, for example, were in Bangkok and traveled to Satun with a night bus, it takes 13 hours, but you can easily sleep, because VIP busses in Thailand are really confortable.
Otherwise if you prefer to travel by train or plane you have to stop respectively in the station or airport of Hat-Yai and then take a minibus to Pak Barra. Hat-Yai is connected to the main locations of Thailand by the air companies Air Asia
and Thai Airways
You can also reach Pak Barra by minibus from Krabi and Trang. From Trang it is also possible to take a ferry and arrive directly to Koh Lipe in 3 hours.
You can reach Koh Lipe by boat also from Koh Lanta and PHi Phi island.
And if you are already in Lamgkawi island in Malaysia you can easily reach Koh Lipe in just one hour ferry trip.
Therefore if you want to go to Koh Lipe directly from your country you have to book a flight to Bangkok. Many companies fly to Bangkok, we flew with Emirates
and we were really fine. Then from Bangkok you have to take a bus to Satun (we suggest to you the night bus so you avoid to lose a day) or the train to Hat-Yai or the Bangkok Hat-Yai flight.