
All you have to do is sign a waiver that will last you the year (you don't have to sign one every time you go), put on a life jacket, and you're good to go. If you have stuff you don't want getting wet (i.e. your purse, your phone, your wallet), they have lockers you can use that are also free. The kayaks aren't legit kayaks, because they're open. You're not tucking your legs inside something, so it's a lot safer if you've never gotten into a real kayak before.
Now, you'll definitely get your backside wet. There's no escaping it. I'd recommend wearing something besides denim - something that will dry quickly. But unless you're purposely slinging water everywhere because you think it's fun (and as long as you don't try really hard to flip your kayak), you can probably tuck your phone or camera into the front of your life jacket so you can take pictures...or text people to make them jealous.
So if you're bored and broke on a nice day, this can be something fun to do. I did have fun, but I must admit I got kind of bored with it. You have to stay within the set boundaries so that you don't end up down the river and out into the ocean. I'm used to being on a fast moving river where the scenery is constantly changing. Here, I just rode around in circles and got excited the couple of times waves came in. Otherwise...eh.
Ultimately, I'd go again. It's something different to do, especially if you're wanting to escape being in the city. And once again...it's FREE. That's a major draw. And when you're with good people, it will always be fun.