Junquillal is great to beach to Surf and practice other aquatic sports. There is a beach break in Junquillal, located on the main beach at the north side, it is a very constant beach break, with right and left waves, will work better with a southwest swell and preferring when the tide is going up. The point is not as crowded as Playa Negra or Avellanas but the days where you can be the only one on the water are over.
There is also an outer reef near Playa Blanca for those of you who like more adventure, there is also a left that breaks with special swell conditions on the reef on the south part of the beach.
You will can also go boogie boarding on the same surf spots, and for those of you who just want to ride the waves for fun, the entire beach is great to do boogie boarding. On low tide the beach will be perfect to go from one side to the other and back on a skim board.
Pretty much on the entire beach but mostly on Playa Blanca (north) you enjoy snorkeling, Playa Blanca has no so deep waters with lots of reefs where tons of fishes, sea turtles, and sting rays among many other sea creatures.
There are some reef rocks over the beach that are great spots for fishing on low tide, you will see the locals fishing over there go ahead and take a detour on your walk, besides a different view of the beach you will also see tide pools full of sea urchin ( don't swim in there!!), crabs and all sorts of funny creatures. Sometimes you can get fresh fish form the locals right there for a reasonable price.