I would head for the filter plant for sure. I have taken a beginners class (all high school kids) there three years in a row and never had any problems. It's pretty much safe to swim anywhere, but there's still some decent drops (remember, everything is relative). This year we took a few kids that did good on filter plant up to do bridges, and that was good too. If they have no experience though, I wouldn't go straight to bridges. If you need help, I might be available next week during the evenings.