Heck yeah I've passed out while I was grappling. I was grappling another more experienced woman and she has a killer lapel chocke, anyways, I went out so fast I didn't even notice the transition. While I was out it was like I was dreaming. However, when I started to come around, it felt like I was swirling in a toilet bowl. My head was spinning around and around. My goodness I thought it would never stop. Anyways, don't worry about passing out in a tournament. They only way you should fell bad or ashamed about passing out is if you are being tough, You know, holding out as long as you can, then you should feel ashamed, because you know it is comming. That is bad jiu-jitsu.