I can't think of any conditions that would preclude the use of this gun, unless of course you're going after 100lb tuna. The choice you need to make is what length is best suitable for your conditions. I'm no expert on California diving. Here in Florida 110 - 120cm is the go to size.
Dan, quick question. I couldn't find a way to PM you so i thought i'd ask through here. I saw your post in Floats & Boards about using a small kayak as a float? I don't know if it'd fit in my car but i thought it was a really good idea and i was wondering if you ever followed through with it? I was originally looking at either the Banks Board or the Kayak Kaddy. I don't know if anyone on here has used that as a float, but saying i'm going to be doing almost all shore dives the kayak seemed like a better option. Sorry if i'm rambling, i am just really excited to finally follow through with something i've waned to do for a long time, and i want to do everything right because $$$ is not on my side. But, rather do it right and spend a base amount rather than to mess up and spend more! Thanks again!!!