I only ever regret one dive. It wasn't due to safety or anything, nothing bad happened it was just, not worth the trouble and complete crap. In Arizona, there is really only one place to dive in the state (a lake) just outside of Phoenix and it only has 2 places to really dive from unless you go out on a pontoon boat or something. One of them is almost guaranteed to be complete crap for about 8 months out of the year (summer/heat). The other just about requires a 4x4 or being incredibly careful in a non 4x4 (twisty, dirt road descending a small mountain) to get to what COULD be made into a good place for divers, but the city/state doesn't want to put any effort into making it a "diver only zone" in a place with very limited diving yet, a good population of divers. So it's open to ANYONE and of course ANYONE will be there. Some times there's other divers and it's all good, but many times you'll show up to a group of drunken rednecks and wandering pitbulls, boats buzzing the area, etc. During the winter months and honestly the bigger part of the year it is a pretty cool dive site with several things to see and some times viz up to 50 or so feet. In the hot summer months though, especially with boats buzzing around the viz is usually only about 5 feet or so.
We went out one time because we had not been out for awhile and desperately needed to practice and refresh our skills and I'm kind of against the whole pool thing. Upon arriving we were greeted by the drunken rednecks and wandering pitbulls. Once we got down to the bottom where you enter (which is a hike down a steep embankment) we were met by about a 10 foot wide line of mulch and sludge that was lining the lake (I heard this happens when they're trying to fill it back up as it's a reservoir). Once we got under the viz was terrible, about 3-5 feet and just, brown. It was like diving in poopy sludge. I had brought 4 tanks, 2 for both of us to make 2 dives but we called it after the first dive due to being baked by the 110 degree temps outside and other conditions. With all that working against us we decided we would never dive there again. We hated it. We didn't want such a place to ruin diving for us when we've dived places like California, Florida and the Keys and want to dive Internationally as well. There's too many better options out there. We've dived in other places since but never that lake again and never will. It could be made into a solid place for locals but it is so situational and the state/city doesn't even know what a diver is nor do they care. Unfortunate, really. Props to the people who try to make it work there and get people into the sport, many of which will probably stop because they don't have a worthwhile place to dive locally.