Well, there are a few murky, gross resevoirs here (lakes, some call them) that they do open waters in. I said "heck no". If can't see 5 feet in front of me, I won't do it! So, once a month the scuba shop we did our confined in travels to Homestead Crater in Utah. It is about a 7 hour drive, but I am more than willing to do it! The is also another place in New Mexico that another shop does the cert in.