Mr Carcharodon
Contributor
You really need to plan for cold water. Most of the northern channel islands trips I go on have more than 3 out of 4 divers diving dry. That is not to say that you cannot dive wet but doing more than about three dives a day may not be realistic as your core body temperature drops. Also getting cold over the course of a dive puts you at greater risk for DCS because your peripheral circulation shuts down to a significant degree so please do dive conservatively with respect to no decompression limits. You really should plan on several local dive trips to get your exposure protection, weighting and buoyancy sorted out before committing to a multi-day trip where there may not be much opportunity to fix things that are not right. California diving can be very good but please go slowly enough to make it enjoyable for yourself.