If you like looking at fish, the Waikiki Aquarium is a nice, small to medium sized Aquarium with a good sampling of Hawaiian and near Pacific sea life. Adults pay $12 to enter, and there are various Military, Senior and Kama’aina discounts.
As a Kama’aina (local with proof of residence) I paid $8 and it was well worth it. I was able to study the fish I’m trying to catch, learn how coral reefs are built by nature and assisted by man, and see some huge broodstock moi (Pacific threadfin).
My favorite type of Hawaiian fish are the chubby goatfish. The aquarium had 3, but in separate tanks.
There’s a tide pool exhibit on the outside of the indoor Aquarium packed with the near shore fish like humus, aholehole, mullet, butterfly fish, kala, enenue, etc. It was interesting to see that most of the carnivores frequented the shallow reef ledge where the wave action washed through. So that supported a fishing adage I had heard before: fish like to feed in the shallows, very close to shore, so no need cast too far.
After viewing the captive fish I left the Aquarium and walked to the beach behind it. That area is a permanent Marine Life Conservation District. Here’s a shot of the area looking west, behind the Aquarium. If you get a chance to walk out on the rock wall perpendicular to the coast line, look closely on the calm, west side and you may see aha (stickfish), papio (jack crevalle) and oio (bonefish). Pretty cool to see wild, free fish cruising around after seeing the Aquarium inhabitants. Don’t try to catch them though, they are permanently protected and the fine is pretty steep!