North of Kona is Puako. All along thwe shore is good there, but especially at lot 56. Park by the road and enter at the beach access. swim out to the edge of the lava and drop. there is a lot of structure and swim throughs. South of Kona two step at the place of refuge is a must dive. Some of the best coral in Hawaii around the bowl. Of course you must do the manta dive, a bucket list dive for sure.
Doug