My wife and I dove with Humboldt/Waterhorse Charters when we were out there last year. Had a great experience with them and would certainly recommend them, but haven't been on any of the other boats in the area. I'm mixed on their Coronado Islands itinerary. Diving with the sea lions was absolutely fantastic, but other than that I wasn't overly impressed with the sites. The third dive in particular, away from the sea lion colony, had very little besides sea urchins. Humboldt rents tanks, but I don't believe it rents other gear, so you'd want to inquire about that in advance.
James
James