It's a great way to go. Bus or tram from city center to the dock. Get info at http://tinyurl.com/cmof848.

Hi Gavin,

I'm not sure about the cost of the ferry. Depending on your timeframe, a flight on Norwegian air would cost about 88€ one way.

I always thought a ferry trip to or from Stockholm to Helsinki sounded fun but I've read in the Swedish newspapers recently about a couple of incidents that happened on two different occasions. (All within the past two weeks). The first was about a young lady that went missing after partying with her boyfriend and others. She went alone to the top deck to smoke and never returned. The authorities are calling it an accidental overboard death but they have not recovered her body. The second was a guy who lit a towel on fire in his berth. The staff was able to extinguish the fire but smoke was billowing in the halls which I'm sure was unsettling for the other passengers. The guy was arrested.

I read on another forum site about these ferry trips to Finland as people were commenting on the first incident. They are relatively cheap and people do these to drink themselves into oblivion. Most restaurant buffés offer unlimited table wine with the meal. Some say they will never ever step foot on this type of boat to avoid being trapped onboard with a bunch of drunk fools.

Where can I buy the ship ticket ?
You can purchase directly from whichever company you want to travel with or a ferry booking agency. One is known more as the young folk/party line and the other as the older/buffet line.

Is it expensive when compare with air flight ticket?
There are a range of prices from inside cabins deep in the ship to outside suites. I don't remember if you can book a berth in a cabin shared with strangers on any of the lines. When I was looking, the prices were per cabin.
That said, an inside lower deck cabin cost similar to the flight. Better cabins cost a lot more.

Is the Pier close to the city ??
The ships dock at the market harbor in the center of Helsinki. I'm not sure if all the ships dock at the same place in Stockholm. I saw one docking near the palace, so that is near the city center there.
The airports in both cities are out a ways, so if you fly instead you must get to HEL via bus or taxi and from ARN you take a bus or train.

Many people like to take the ferry one way to see the islands. Finland is all about water, so the locals love to go by boat. But you won't see much is you are traveling in the winter when the days are short.

The buffet dinners are supposed to be generous, but expensive.