Waimanalo beach - I actually got this one mixed up with Lanikai. I have no idea why. Lanikai is a great beach and worth a visit but Waimanalo was the one I was thinking of when I said it was the most scenic and good for boogie boarding.

Waimea Bay - This has a fun shore break and some decent snorkelling on the north side of the bay where the water is more calm.

Waimea Valley - directly behind Waimea Bay is gorgeous and worth exploring.

Laie point - Hopefully you are staying on the north shore. If so lucky you, head to Laie point just before sunrise. Watching the sun come up here is beautiful. If you are not on the north shore, its still worth it to get up early and go see it.