I wonder why I don't see California marketed more heavily as a dive destination for tourist divers from elsewhere in the U.S. Instead of thinking of it as place people dive locally, or leave from to dive elsewhere, what's keeping it from becoming more of a place people from elsewhere travel to for a dive trip?
I'll take a stab at answering that for you. I think there are several reasons that we don't see California as being marketed as a dive destination.
1. Marketing funds are in limited supply, so it makes sense to spend them where they will get the most return. California has a lot of other attractions for visitors, which is why you see Disneyland, Yosemite, beaches, Hollywood, wine country, skiing, the Golden Gate Bridge, etc prominently featured in tourism ads.
2. In addition to cold, California water typically has poor viz. We're totally stoked (sorry... that's Californian for "excited") to get 30 feet viz on a beach dive; 20 feet is closer to typical... and we're happy to have it. We'll even dive in 10 feet viz (we just won't be too stoked about it.)
3. Boat diving is available from San Diego and Long Beach (these are the two big ones in So Cal, although some dive boats leave from other cities), but the recreational sites serviced by these boats from the mainland tend to be wrecks that are in ~100 feet of water. This means colder and darker... difficult to market to tourists. San Diego probably does a better tourist diving business than anywhere else in the state, largely because it's a tourist destination already and it has a handful of wrecks that are a fairly short boat ride from the marina.
4. If you want decent viz (but still cold water...) you have to hop over to the Channel Islands, which typically means a two-hour ride on a dive boat from Long Beach to Catalina Island. The kelp forests and giant black sea bass there are cool, and there's a fair amount of sharks in the neighborhood... but it would take a
lot of creative marketing to convince people to travel to So Cal just so they can spend two hours on a dive boat (each way!) and bundle up in 7mm neoprene for a
chance at seeing some giant sea bass drifting through the kelp.
5. Even if people wanted to do it, they would have to be able to handle the cold water diving. People with no experience in cold water diving tend to get themselves in a lot of trouble diving out here... the cold and thick neoprene causes some serious stress. And there's the rub: the vast majority of people with experience diving cold water aren't going to seek out a vacation with cold water diving when they could go to warm water instead! I know I wouldn't...
This is just my take on why California isn't much of a dive tourism destination. With that said, I'm sure if any of you are in the neighborhood and interested in a local beach dive, there are plenty of us here on SB that would be willing to show you around.