The Whitesaddle Goatfish, Parupeneus porphyreus, or Kumu in Hawaiian. This one was under a coral ledge in Waikiki.
Kumu is one of the most popular and, these days, uncommon of the goatfish in Hawaii. Its soft, flaky, white meat is treasured in Hawaii and, even when I was a kid, was considered quite a catch when you could find one. You don't see many anymore, probably doomed by their own tastiness. The ancient Hawaiians offered kumu to the gods because of their red color, which was meaningful for rituals. The few I saw were hiding under coral ledges as opposed to their more free ranging goatfish cousin, the moana, which could be seen freely roaming the reef during the day.
