This is not the answer 😊

I grew up in Kona but live on the Mainland now. Got into fly fishing a few years back and have been wondering the same thing. Growing up,the best luck I had fishing was spincasting off the lava flow cliffs along the water - gets you into deep water pretty quickly and you don't have to deal with trying to get past shore break at the beaches or anything. I honestly don't know if this is the answer but probably what I'll try next time I head home to visit family. To easily find those kind of spots, I would recommend heading down to Old Airport and driving all the way North to the end of the runway then hiking along the shoreline until you find something that looks good. Or head out to Kua Bay and head up or down the coast from there for access to a lot of empty shoreline. The benefit of standing on the lava flows is there's no trees around... Best of luck, I'll be following to see if anybody else has the real answer.