Thanks for the info on Hanauma. I'll give it a try. Funny thing is, on Tripadvisor, the reviewers give it either 1 star or 5 stars!
I can understand the 1 star or 5 stars reviews.
If you just go and not really know what to expect and where to snorkel, then you might give a 1 star. You might not know that there is a small charge to get in and a charge to ride the trolley. And you might decide to walk down and then UP. You might not know that you need to "leave the shallows of the beach" to see the fish. You might not know to look at the waters from the top, notice that you can avoid the coral by going to the far left or right and see lots of fish.
If you do your homework and know what to expect, you probably will give it 5 stars. We walk down, pay to ride up, sit to the far right or far left, and swim out beyond the coral reefs. We also go early in the morning. We've stood in the water just before the coral and watched the fish swim between our legs. We would give it 5 + stars every single time.