I like to think of it this way: What are you trying to accomplish? What is the right tool to accomplish it? Agreed with Eric on determining your hunting intent. There are all sorts of float types. For the Monterey and north area you're looking at gear carrying and float line floats. Gear carrying floats like inter tubes, boogy boards, and banks boards are commonly used for shore diving to attach guns, stringers, measure sticks, dry bag stuff, etc.. The intent of these it to give you a home base to attach all your gear carrying it to and from the dive location. These are not good to drag around on the end of your float line while hunting as they're very cumbersome and definitely get caught in the kelp. I suggest you bring an anchor rope or "kelp clip" and once you reach your dive location your tie the bulky gear float off and only return to it when you need to. Then you can break off with your gun, float line, and float to be as mobile as possible.

In Monterey and north you're likely hunting rock fish that are not of reasonable risk to run far or dive deeper than you already are so you don't need anything in the 1 ATM blue water float range. They are likely to run to a hole or crack and get stuck requiring returning dives. There's also a likelihood visibility will not be good enough to see the holes and cracks you'd like to investigate from the surface. This is where float lines come in. They let you leave your gun and return to the surface while maintaining confidence you'll find your gun again on a healthy safe new breath to either hunt the hole or recover the fish. With a reel you can return to the surface after shooting a fish while holding onto your gun. I would not advise leaving your gun as a marker because you're just as likely to loose it as the hole you're marking. So I prefer and suggest you use the float line for Monterey and north just as Eric has.

Where the float comes in. Not all float lines naturally make it to the surface. Some have tuna clips on both ends which cause the trailing end to sink. You can remove them but the remaining hardware still weighs it down. Sometimes light current causes the line to stay below the surface. If you keep a hold of it during a return to surface then there's no problem. In my experience it is not always a guarantee you can keep a hold on the line coming up. You're then stuck looking for the end of your line in the vast ocean. Adding a brightly colored float is a good tool to make locating your float line easier. It keeps one end solidly on the surface. It also makes it easier for your dive partners to find. The trade off is the larger the profile of the float the higher likelihood of it getting caught in the kelp. For scale as I mentioned before I used a red/white striped crab pot float. Worked good for visibility but was a bear to pull through the kelp. I've seen a lot of kelp carrots work better than the crab float but still hang up. I went with a Gannet snake float (Yellow) and still use it today. It does get hung up every once and awhile but I find it to be worth the trade off of ensuring I can find my line and ultimately my gun. As with all things forum, this is my personal take on the matter and I'm open to questions. Good on you for seeking information.