Last weekend we ventured down to Gwangalli for the Eobang Festival. The festival is a celebration of spring and the ocean. Eobang is translated as the spirit of the fishermen and you can see a reenactment of the old traditional costumes of the fishermen. The kids also fly kites, there are a ton of arts and crafts and styrofoam blocks for the kids to build forts with.
Of course there is a ton of Soju, Mackgoli and food.
To get to Gwangalli beach which is really much better than Haeundae (if you are looking for a nice day to relax seaside) Take line 2 heading towards Haeundae on the busan subway and get off at Geumnyeonsan Station. Exit and head straight towards the beach. (I am pretty sure any of the odd number exits will take you east towards the beach)