If you want to go to Ko Lana, you have to to it by Express Boat from Krabi.Depending on the weather it takes around 2 hours.
Boat to Ko Lanta Impressions of the coast around Krabi
You meet many back packers on these Express Boats between the islands. And you can always change your impressions with the others and get new infos about where to stay or to go.
Thailand The Express Boat to Ko Lanta. Overcrowded as always...