A few items outside the general discussion. You need to have a good dive light for socal diving, not only will this let you look into nooks and cranies for marine life, but you can use it to signal to your buddy so you stay together. Compass: you gotta have a compass to navigate to and from the boat on most dives. The boats provide a single light blanket and pillow. You may want to include a light sleeping bag in your kit, or plan for some sleep wear that will keep you warm. Foam ear plugs or noise cancelling headphones can be a godsend in the noisy boat dorm. There is not much room for luggage on the boat. I bring two bags: one has my "bunk gear" and the other my "day gear". Once you get wet, you will not be allowed back into the bunk area, so when I leave the bunk in the morning I have all the items I want with me during the day (cell phone, toiletries, change of clothes, shower towel, jacket, sunglasses, etc.) in my small bag. (I find a place out of the way to stash this bag.) After diving I strip off my wetsuit, shower, don my clothes, and then I can go to the bunk. 110 volt outlets on some boats can go pretty fast, bring a multi-plug so you can share an outlet for phone/battery charging. Streamline you dive kit. Avoid looking like an xmas tree with a bunch of ornaments hanging on it. Kelp strands will hang up on all that crap and slow you down. Be sure to look above you in the kelp forest, diving here is very three dimensional; you will see marine life in front of you, below you, behind you and especially above you in the kelp canopy. Have fun!