I really liked this episode! I enjoyed how they showed the injuries which a person could sustain if they fell 35 feet into shallow water with or without a mattress but mostly I'm delighted at how they showed that such a fall is possible if you have the right training. That's pretty awesome.
The stone cannonballs was also interesting. I always like it when they bring out a canon, although learning about how they'd messed up and damaged someone's house really reinforced the whole 'don't try this at home' warning they give.