Ok, First things first. If it has been 6 months or more since your last dive (particularly if it has been years) a refresher course would be advisable. If you choose to skip that, I would recommend hiring a DM to escort you and do a quick refresher.
Second, it does not have to be either or. If you go to San Diego first, do a dive or two there. They have nice diving, good kelp and there are 1/2 day boats too. Then come to Los Angeles for more diving.
Los Angeles has lots of great dives. Catalina is you best bet for good visibility and diving most of the time. I would take a dive boat out of Long Beach, 3 dives, sleep on the boat the night before, food and air included (Great Escape and others), transportation to and from the island and a variety of dive sites. Catalina Avalon Dive Park is good too, but more logistics, take express over, lug gear to dive site etc.
Lots of good shore diving in Los Angeles. http://www.sandeaters.org has a description of dive sites in SoCal. Visibility will be zero to 40 feet with 10-15 being common here on the mainland. At Catalina 20-60 feet is more normal.
Please note dive shops here rent tanks, computers, guages, 1st & 2nd stages, octo, BC and wetsuits for $45-60US per day (sport chalet pick up one day, rental is second day, return 3d day). You need to supply your own mask, fins, boots, gloves and snorkle if you want one (required in laguna beach). On the mainland there are only 3 shops that rent mask, fins, snorkle, boots and gloves and they charge $100 give or take a bit for all that.
Second, it does not have to be either or. If you go to San Diego first, do a dive or two there. They have nice diving, good kelp and there are 1/2 day boats too. Then come to Los Angeles for more diving.
Los Angeles has lots of great dives. Catalina is you best bet for good visibility and diving most of the time. I would take a dive boat out of Long Beach, 3 dives, sleep on the boat the night before, food and air included (Great Escape and others), transportation to and from the island and a variety of dive sites. Catalina Avalon Dive Park is good too, but more logistics, take express over, lug gear to dive site etc.
Lots of good shore diving in Los Angeles. http://www.sandeaters.org has a description of dive sites in SoCal. Visibility will be zero to 40 feet with 10-15 being common here on the mainland. At Catalina 20-60 feet is more normal.
Please note dive shops here rent tanks, computers, guages, 1st & 2nd stages, octo, BC and wetsuits for $45-60US per day (sport chalet pick up one day, rental is second day, return 3d day). You need to supply your own mask, fins, boots, gloves and snorkle if you want one (required in laguna beach). On the mainland there are only 3 shops that rent mask, fins, snorkle, boots and gloves and they charge $100 give or take a bit for all that.