If you are already doing the Makapu’u Lighthouse Hike (which is amazing,) you might also want to take the dirt path from the parking lot over to the coast.
It’s a dry walk, and it was dusty in June. I recommend lots of water, and possibly a snack. On the upside, it’s not a hard walk because it’s completely flat.
Sometimes the locals go there to fish, so beware of stray hooks and lines. Also, remember that the waves break on the rocks! Keep your distance. People are sometimes swept off the ledges, and the sea is very rough in this area so you could get seriously hurt.
It’s really more about sitting at a safe distance and watching the waves splash over the rocks. I went at low tide, so I managed to see a few fish and some crabs.
That was fun, but I was very wary of not stepping on any wet rocks. If the rocks are wet, waves are probably breaking on them. So, steer clear of wet rocks.
Overall, it’s worth the walk if you’ve already done the lighthouse hike and you have some time leftover. However, I wouldn’t brave the crowded parking lot just for the coastal area, because there are prettier places on Oahu that are less crowded.