I have dove different places on Maui and Kona - including boat dives. Mala Ramp is by far the best site in all respects. Forget about Black Rock. It is too expensive to park there and a long walk (1/2 mile) to the beach with the tank and gears. This is particularly difficult for an underwater photographer like myself to carry things back and forth. The surf can also be bad at Black Rock. Old Airport Rd and Mile 14 are not that great either. Nothing special about them. During my Mala dive, however, I saw 2 white tips, lots of fishes, at least 3 different turtles, and eagle rays. This is a good beginner dive site, but an advance diver will enjoy this also (I am a dive master myself). The depth is shallow, less than 30 ft. The current is almost non-existent. This makes picture taking very easy and with clear water. Entrance is very easy and simple. However, I would highly recommend that new divers to this site follow a dive tour during the first dive since there is boat traffic and you need to know the swim path to avoid boats. There are 2 shops nearby that can arrange the dives with reasonable price. The visibility is excellent. Some of my best Maui pictures were taken in this place. This should be the first dive of your Maui trip.