Almost drown on white water rafting trip

This was a real experience when I was 18 or so with my girlfriend Candy at the time; and we decided to go on a weekend trip to Algonquin park ( Ontario ) on a white water rafting trip. Sounds fun right?

It certainly was fun...for a while; some of those rapids were certainly -far- wilder and more intense than I was expecting. Any ways; closer to the end of the day, it was sunny and hot out so they get to a more calm but still fast moving part of the river and everyone jumps in ( with life vests on ) and you just float down the river for a couple miles.

So I'm just sort of floating around the boat, then end up in front of the boat somehow, and it suddenly catches up with me and essentially runs me over; and I saw it just before it hit me; and thought it would be a good idea to try to grab on to it and push myself underwater; then hopefully just pop back up behind it. Well I popped up alright, ( because of life vest ) but I popped up beneath the boat, where there was only about an inch of air trapped beneath in this tiny pocket for trying to breathe. ( Very difficult ). I tried with all my might to push myself back down and get away from the bottom, but I was trapped.

I started desperately trying to lay as flat as possible to try to push my face up to breath that inch of air; but waves were causing me to slowly, partially drown...and I thought for sure I was going to die this way.

This went on for a few minutes or so ( it felt like ); and then boom; my hits smack into a rock and jolted me free and out the back of the boat; where I was coughing and trying ( unsuccessfully ) to communicate how I just almost drowned.