Bus
By rail or bus from Thailand
Bangkok - Hat Yai - Sungai Golok - Kota Bharu - Kuala Besut

Take a train or bus from Bangkok to Haadyai (10 to 16 hours) then its 4 hours more to Sungai Golok. From there cross the Malaysian border to Rantau Panjang and take a taxi (RM4per px) to Kota Bharu.

By bus from Kuala Lumpur
Go to Hentian Bas Putra opposite Putra World Trade Centre where you can purchase ticket direct to Kuala Besut Jetty

By bus from Singapore
Bus depart daily (7.30pm) from Lavender Street to Kota Bharu. Inform bus driver you want o stop at Jerteh. Take taxi from Jerteh to Kuala Besut which going to take about 20mins drive to arrive.

Air
From K. Lumpur fly to Kota Bharu.
From K. Bharu airport take a taxi to Kuala Besut jetty. (45 minutes journey costing RM 70.00). (Do not get swayed by people trying to take you to Tok Bali jetty.)

Or fly from Bangkok to Naratiwat (1hour 20 mins) then minibus to Sungai Golok (2-3 hours).

From Singapore fly to Kota Bharu. Direct flight available from Singapore to Kota Bharu 4 tiems a week.