A short taxi ride from Haeundae’s wall of humanity is the much more laid back Song Jeong Beach. The shallow surf is great for swimming and there are several good restaurants and bars nearby.
You have several options to get there:
There are seven daily trains there from Bujeon and Haeundae Stations.
Take the Subway all the way to the end of the line at Jangsan. Hop in a taxi and say "Song Jeong Beach-y, ga-chuseo) ??????
From Busan Station: Take Bus No.139, 140, 239, 302-1
From Haeundae Station (Exit 7)→ Take Bus No. 100, 100-1, 139, 142