Would HIGHLY recommend a tour/excursion through Coming2 and Scubaquatic (which is in our hotel lobby)- I did a full day scuba excursion to Catalina Island and my wife snorkeled- it was fantastic, well organized, and very professional, and a great lunch on Catalina. I can’t speak on any other tours but as a newer diver- I felt safe, respected, and it was a good deal for what we paid... Juan was an excellent divemaster.
They pick you up and drop you off at the front entrance in a nice charter bus- it is clear that safety is a priority. The scuba equipment is in good condition- and they set everything up for you. We did 2 dives, one on 'the wall' and another in the reef. The divers are split into small groups, each with a dive master.
Catalina island was very pretty- great lunch but gross bathrooms and the vendors there are a little pushy.
Overall very much enjoyed the experience! Tip them well!