From Krabi Minibus to Koh lanta all year. Mid-October to mid-May there are boat from Krabi to Ban Saladan pier on the northern tip of Koh lanta. 2 time per day.

Frome phuket Mid-October to mid-May there are boat from Pheket to Ban Saladan pier on the northern tip of Koh lanta. 2 time per day and the boats pass Koh Phi Phi also using this service to Koh lanta if you in Koh PhiPhi.

From Trang There is also an overland route which is used year-round by minivans from trang

If you need tranfer from somewhere let me know...