Waimea Bay is one of the best beaches on Oahu due to the fine sand, incredibly clear, blue water, and an awesome rock to jump off.
The drawback of it being such an incredible beach is that it is quite popular for locals and visitors alike. It is a pretty large beach, though, so you shouldn’t have trouble finding your perfect spot to relax.
The water is perfect for snorkeling and the best place to snorkel to the left of the large rock as there is some reef there where you can find more fish and even turtles. Another fun thing to do is to swim in the tunnels under the rock!
If you’re daring enough you can jump off the rock. There are always people up there so you can follow them and see where they jump from. There are various heights to accommodate all fear levels.