If you have your heart set on sitting by the water, get the first time available (11:30, I think), show up early, and ask for a waterside table "pretty please, with sugar on top". The downside of lunch time is they don't serve the surf-n-turf or filet mignon.
Other than that, I don't see much difference in the reservation times. Waterside is generally preferred and they'll sometimes let you wait for a seat by the water but it's less likely after the first seating and pretty much luck-of-the-draw as closing time approaches.