Langkawi Online gives a summary of options for travelling to Langkawi. I concentrate here on the trip from Penang.
Air Asia can be cheap, if you get a promotional fare. It is about 25 minutes in the air, but from when we left home by taxi to when we were in our hotel room about four hours had elapsed. Which was about the same amount of time as driving and catching the ferry, although the flight was less strenuous.
Firefly can offer cheap fares to LGK.
Malaysian Airlines flies to LGK via KUL, and thus is not very convenient or fast. It has no direct flights.
Unless you go by air, you are going to have to catch another form of transport, and then a ferry. In Malaysia they haven’t generally grasped the concept of a convenient (in terms of time and proximity) connection between different modes of transport. You need to check timetables to find the least inconvenient schedule for you. As you cannot book in advance for the ferries from Kuala Kedah and Kuala Perlis you cannot be sure of when you will reach Langkawi.
Try http://www.ticket4u.com.my/plusliner/ Please note that the ferry terminal is not particularly near Alor Star. It is a 15 minute drive to Kuala Kedah. Instead, consider Penang to Kuala Perlis. I have yet to take a bus on this route, but will possibly try it next time.
For more details on the bus, see this mid-2014 blog of the trip.
In my opinion, the real choice is between flying or driving and catching the ferry – if you are living here and have a car. With a car you can plan when you will be at the ferry terminal in order to maximise your chances of obtaining a ticket, and minimise your waiting time. Thus I have done this trip twice by car. Failing this, a bus is the next best. By car you can take the E1 motorway to Alor Star (Exit 177) and use the local roads to Kuala Perlis, and this is the shorter route.
However, the local roads are not so safe, and certainly not at night, when you may have straying animals, and plenty of vehicles with no lights, to contend with. Or you can take the E1 further north to Exit 194, and have a dual carriageway all the way, but the distance is considerably greater, and it takes a little longer. I feel it is the safer and easier option. I have paid between RM10 and RM12 per day (24 hours) for undercover parking at Kuala Perlis.
There is a ferry directly from Penang to Langkawi, which takes 2 hours 45 minutes, according to the schedule. We’ve been told by friends the ferry directly from Penang to Langkawi can be terrible, if the seas are choppy. Reading the reviews on Trip Advisor really put us off. They said the same, but worse.
There are also ferries from Kuala Kedah (1 hour 45 minutes to Langkawi), which is on the coast about 15 minutes drive from Alor Star; and Kuala Perlis (1 hour 15 minutes to Langkawi), which is about 45 minutes drive from Alor Star.
http://www.langkawi-ferry.com/Home/Schedule.aspx says, “ONLINE BOOKING ONLY AVAILABLE FOR PENANG TO LANGKAWI AND PENANG TO MEDAN” A friend rang to confirm that you can only buy tickets on the day, at the ferry terminals.
My thoughts? The ferry from Kuala Perlis is quicker, in reality the crossing taking one hour, and the terminal area seems more organised than Kuala Kedah. I prefer the shorter crossing time and slightly more driving time.
KTM has only two trains a day to Alor Star or Arau, as their schedule shows. Then you would have to connect to the terminal by taxi or bus. Unless you really, really want to catch the train, it is the least attractive option.
A TRIP FROM PENANG TO LANGKAWI BY CAR AND FERRY – To be published soon.