Really cool, wish they had audio!
BTW, you should have patented the snowboard. You were standing on a gold mine.
Thanks!
Audio is all in my mind. The highs and lows, based on displacement.
Those were the days before mufflers and decibel limits.
Later on, we found one of those big old round Coca Cola signs, and took it out to a soil conservation lake that had a dam that, at the time, seemed like it was 100 feet tall.
That sign would slid across the grass on the dam and pick up speed, until you discovered there as a barbed wire fence right at the base.
Great times, wouldn't trade them.