May I make a suggestion? I have stayed at this hotel and was not pleased at all. The facility itself is just fine, but the location is horrendous. You are right smack in the middle of the noisiest, busiest area, on a very public, narrow beach (one that is not very clean and is usually pretty crowded, including homeless people).
There are much nicer Marriotts in HNL...i.e., the JW Marriott Ko Olina is beautiful. There is just no comparison. Unless there's a reason you want to be in Waikiki. I just don't understand why anyone would pick the Waikiki Marriott over the Ko Olina one, if you have a choice.