Going to an amusement park on my period!?

I'm going to an amusement park with one guy friend (were not dating) but I just started my period today. I had a feeling I was going to start because yesterday I had cramps and back ache and I felt nauseous. On the first day my flow isn't too bad, usually medium to light buy I'm wondering if I'll be able to go on the big rides and stuff and one of them is a water ride that gets you super soaked. I dont want to pet my period stop my fun so how can I make sure I don't leak??? Also I only ever use pads, not tampons.