Although much of the ʻĀhihi-Kīnaʻu Natural Area Reserve is currently (as of this writing) closed to the public, one of the areas open to the public is Waiala Cove and that is where we went snorkeling.
We parked in the larger parking lot with a very rough surface about a quarter mile south of Waiala Cove. There were two port-a-potties in this parking lot and it was a leisurely stroll along the road back to Waiala Cove.
There is a sign on the south part of Waiala Cove warning about the negative environmental impact of walking on the coral and other things in that area of the cove. This is also the more difficult side to enter the cove from because of sharp rocks and coral. The better entrance is at the north end of the cove where there is a cement block at the entry point that can be used to stand or sit on while adjust snorkeling gear.
When you enter the code from the area near the concrete block, the cove appears as shown in the next two photographs.
One of the appealing features of Waiala Cove for those who do not snorkel (such as very young children) is that fish will swim right up near and around people standing in the water near the concrete block without going very far out. In fact, you wouldn't want to go too far out because there are sharp rocks, coral, and lava that waves can push you into if you're not ready to snorkel.
There is a narrow corridor starting at the concrete block that waders can walk in or snorkelers can use to adjust to the water. The bottom here is made up of generally smooth rocks and pebbles and fish swim in and around your legs as you walk along.
Unfortunately, we did not learn of Waiala Cove until close to the end of our time on Maui. We liked it so much, however, that we went snorkeling there twice in two days. The first day was in the later morning and the second day was in the early morning. Mornings seemed to generally be better for snorkeling because the water is calmer, there are fewer other people there, and the water is clearer because of the calmer water and fewer people stirring up sand. When we went in the later morning, we shared the cove with about 15 people. When we went around 6 am the second time, we had the cove to ourselves.
Because it is a cove, Waiala Cove is a nice place for beginning and intermediate snorkelers. The cove protects the snorkeler from the worst of the ocean's waves. However, early mornings seem to be calmer even in the cove and snorkelers still need to be aware of how close they are to sharp rocks and coral in the cove as occasional waves come in hard enough to push snorkelers into or on top of these rocks and coral.
There is very little legal parking right next to the cove, but there is a decent sized dirt parking lot just past (south of) the cove.
The Ahihi-Kinau Natural Area Reserve has other interesting features besides Waiala Cove, but many of them are not currently open to the public. However, even walking from the dirt parking lot to the cove has some interesting lava on the side of the road.
Waiala Cove is a beautiful cove with several species of fish readily viewed in its relatively clear water. There are also some interesting features on the bottom of the cove. It's a relatively small cove and the parking lot is only moderately sized, so it's often best to get there early to enjoy it at its fullest.