The big island is on my bucket list to do the night Manta feeding. So I’m jealous. I have been to Maui several times. I did only one shore dive, at Black Rock at the Sheraton in Kaanapali. It was ok, nothing special, a few sleeping turtles in caves. The boat dives to not miss would be the Cathedrals on the Island of Lanai and probably Molokini (either inside for calm or drift dive on the backside for more advanced). I used Lahaina Divers both times and had great experiences. They go out every day and you can see where to on their website. Kinda pricey with any dive charter, but worth it for vacation right? And with a charter you don’t need a buddy as they will pair you up with another diver or you can follow the DM/guide. Too bad your trip isn’t a couple months later as I will be in Maui July 14-20, and then Kaui the week after. Have fun!