Baby's First Beach Trip

So, we are taking our first family vacation this weekend to the beach. I'm a first time mom, and was just wondering, besides the obvious sunblock/swimsuit/swim diapers/hat/drinks, what should I take for my 8 month old son? We aren't flying, it's kind of a day trip sort of thing. (We are flying to Phoenix at the end of the month; tips on flying then would be appreciated as well). I just don't want to forget anything.