Better golf and body surfing there. Hanauma Bay for tame snorkeling. meesier42 seems to have some insight though. Probably not a good time for Halona Cove between Sandy Beach and Koko Head.
I didn't even think about Halona and Lanai Lookout, but those are advanced to very advanced dives that you really need someone to show you how to enter and exit safely, not to mention navigate. and you have to time the surf, as both locations amplify the a 3-4 foot surf into 10+ killers and the Molokai Express will gladly take you for a long ride that only the coast guard can save you from.
here is another resource that is valuable.
http://www.shorediving.com/Earth/Hawaii/Oahu/index.htm