By fast train it's only 30 minutes from Sapporo. The slower train takes nearly twice as much time. For some stretches the train runs right along the sea.
From the station you can walk straight down the street until you hit the canal.
From Sapporo, take a train for Y620. It's a 35 minute ride by express or 50 minutes by ordinary train. You can also come by bus from Sapporo Station (Y590, 55 mins). Or if you are on Honshu, look into the 31 hour ferry ride from Maizuru, or shorter trips from Tsuruga, or Niigata. The fares start from just Y6980 for a basic trip -ex Maizuru. Call: Shin-Nihonkai Ferry Co - tel 0134-22-6191, or Osaka Reservation Centre 06-6345-2921, Tokyo Reservation Centre 03-3543-5500, or Nagoya Reservation Centre 052-566-1661.
Walking is good. You can easily walk from the station to the canal. But if you want to see a lot in a short time, catch a Sansaku (sightseeing) bus and pay Y2300 for 3hr 10 minute trip. This ticket doesn't give you admission to each facility, but you do get discounts at the places you visit if you have one of these tickets. Otherwise, buy a one-day in the city ticket for Y750, and this gives you unlimited bus travel all over the city for a day (you can use it on the bus in the picture). It's really good value. Or rent a bicycle in summer (near Otaru station).
Train is the way to go. If you are coming from Sapporo, sit on the right-hand side and you’ll get a beautiful view of the Sea of Japan (or Korea – whichever way you want to look at it). I can’t remember the exact cost but it’s less than 1000\.