Do yourself a favor and get a VIP ticket if you're going to a concert. It gives you exclusive access to a patio and a 19+ bar.
Unfortunately, these tickets were sold out by the time I got my hands on some. This will put you at the mercy of screaming fans which will constantly try to push their way to the front of the stage. Also, wear flip flops (unless you want to ruin your nice shoes). I wore platform sandals so it gave me a bit of leverage for tippy toeing. Parking is $20 from May-Aug and I think $15 from Sept-Apr.
A beach concert in May (regardless of whether or not it is at the beginning or the end of the month) is a BAD idea. I was subjected to pouring rain, heavy winds and quite possibly, a horrible cold (having been outside for 2 hours). Had the weather been amazing, this concert would've been 100x better. However, those are the risks that come with going to an outdoor concert. Can't say I'd be surprised if half the audience went home with a cold though.
Dress appropriately and watch the weather network. Marina was still, nonetheless, stunning in person and made it well worth the experience. I'm thankful that she didn't mess around, go backstage and wait for us to scream and shout at her for an encore (I think her sips of whiskey was helping her keep warm). She's an absolute sweetheart; she also asked the audience to sing 'Happy Birthday' for one of her band members. Marina and the diamonds is a phenomenal singer. Like I said before, WELL WORTH IT!