The Big Island isn't known for surfing, but when an east swell rolls into Isaac Hale Beach Park in Puna, the waves get covered with shortboards. The break is mostly left, off the breakwater that creates a boat ramp into little Pohoiki Bay. The concrete-and-rip-rap structure is also the spot to sunbathe an spectate. You get a view right down the barrels.
The beach park is also known for a small natural warm pool that lies at the backshore in the middle of the bay. Surfers also like the reefy break called Bowls, which is off the park's picnic tables. The scene really amps up on weekends at Isaac Hale (HA-lay), when teens and families come down from all over Puna (the east quadrant of the Big Island) and Hilo. About a mile away is Ahalanui Pond, a county park with a huge man-enhanced seaside pool that features water geothermally heated to 90-degrees-plus.
BTW: Pohoiki Boat ramp is where people leave for lava-viewing boat tours these days, since the viewing site shifted a couple years back from Hawaii Volcanoes National Park, to Kalapana Bay in Puna. You can also walk to the lava flows; Hawaii the Big Island Trailblazer has details.